In the summer of 2009, on a low rise of ground just outside the old walls of Winchester, a team of archaeologists cleared the soil off a grave that had been cut into solid chalk. Cut, not scraped. Someone had gone at the bedrock with an iron tool and shaped a hollow that followed the outline of a human body, with a little rounded niche at one end to cradle the skull. That is careful work.

That is the sort of grave you dig for someone you have decided matters. Inside it lay a young man, 18 to 25 years old, going by the state of his teeth and the growth plates in his long bones. Beside his pelvis, where a purse or a satchel would have hung, was a scallop shell with a hole bored through the hinge so it could be threaded onto a cord. Pecten maximus, the badge of Santiago de Compostela.

He had walked to the far northwestern corner of Spain, or someone had brought the shell back for him, and either way it went into the chalk with him. Radiocarbon dating put the burial in the late 11th or very early 12th century. Then they looked at his feet. The bones of his lower legs and feet carried the marks of Mycobacterium leprae.

Not much of it, honestly. The skeletal damage on him was slight, confined to the extremities, easy to miss and easy to argue over. But when the molecular work came back, published in 2017 by Simon Roffey, Katie Tucker, and their colleagues, the DNA of the bacillus was everywhere in him. Multiple bones, even bones with no visible disease at all.

The strain typed to a lineage called 2F, which today turns up in cases from Central and Western Asia. His diet, judged from the chemistry locked into his bone collagen, looked like the diet of someone with money. So, a young man of some means walking hundreds of miles across France and over the Pyrenees and back with a slow bacterium quietly dismantling the nerves in his feet the whole way. And when he died, somebody laid him in a shaped chalk grave with his pilgrim badge on a hillside cemetery where the same excavations found the same disease in over 85% of the burials they examined.

Thirty-three out of 38 bodies. That hillside was the leprosarium of St. Mary Magdalene, and it is one of the earliest excavated leper hospitals in Western Europe. That number matters later, when we get to other cemeteries where the figure is nothing like as high, and where the question of who actually ended up inside these places gets complicated.

To understand what happened to that young man and to the thousands of others who ended up behind the walls and hedges of a leper house, you have to talk about what the disease actually does to a living body. Every stage of it was visible to the people standing around the sufferer, and every stage was worse than the one before. Mycobacterium leprae is the slowest growing bacterium known to infect human beings. It has to be grown in the footpads of mice, because after a century and a half of trying, nobody has ever cultured it in a laboratory dish.

In that model, the doubling time is somewhere around 12 to 14 days. Compare that to something like E. coli, which doubles in 20 minutes. This organism is in no hurry whatsoever.

It cannot be outrun. It moves at the pace of seasons. The incubation is measured in years; the World Health Organization gives an average of about five years between infection and the first visible signs, with cases stretching out to 20. In 2023, a case report described an 84-year-old man in Canada who had not traveled outside the country in 56 years.

Whatever he picked up, he picked up as a young man, and it sat in him through most of a human lifetime before it announced itself. The bacillus also has a temperature preference. It grows best somewhere around 30 to 35 degrees Celsius, a few degrees below the body’s core. So it colonizes the cool parts.

The skin, the earlobes, the tip of the nose and the lining of the nasal passages, the testes, the peripheral nerves that run close to the surface, particularly the ones that pass over bone at the elbow, the wrist, the knee, the ankle. Everything that happens next is a consequence of that preference. The disease goes for the edges of a person. And it splits, according to what the sufferer’s own immune system decides to do about it.

At one pole, you get what modern medicine calls tuberculoid or paucibacillary leprosy. The immune response comes in hard, walls the organisms off, and produces a small number of well-defined patches on the skin, pale or reddish, dry and dead to sensation, along with a few thickened nerves you can feel like cords under the skin. Comparatively few bacteria in the tissue, comparatively contained. Some of these cases even resolve on their own.

At the other pole is lepromatous or multibacillary leprosy, and this is the version that produced the figure medieval Europe was terrified of. Here, the cell-mediated immune response essentially fails to switch on. The T helper cells never mount a defense, and with nothing standing in its way, the bacillus multiplies without limit. Not thousands of organisms, billions.

A single gram of tissue from an advanced case can hold ten to the ninth bacilli. The lesions start as vague, pale, or coppery macules with edges you cannot quite find. Then the skin of the face begins to thicken from underneath as it fills up with bacteria-stuffed immune cells. The forehead corrugates.

The brows swell into ridges. The nose broadens. The ears thicken and droop and grow nodules along the rim. The lips coarsen.

Medieval physicians and modern textbooks use the same phrase for the result, and it has survived nine centuries because nobody has come up with a better one. Facies leonina, the lion face. The eyebrow hair goes, and it goes in a very particular order, starting at the outer edge and working inward, a sign called madarosis. Then the eyelashes.

A face with no brows and no lashes and thickened folded skin does something to how other people respond to it. Underneath all of that, the real work is happening in the nerves. The primary target of M. leprae is the Schwann cell, the cell that wraps peripheral nerve fibers in insulating myelin.

The bacillus carries a molecule on its surface called phenolic glycolipid 1, unique to this organism, and infected immune cells respond to it by turning on the myelin sheaths themselves. The nerve demyelinates, then it degenerates, then it dies. And when a nerve dies, two things happen. The muscles it supplied go slack and waste away.

And the skin it supplied stops reporting. Everything grotesque about advanced leprosy comes out of that second fact. The disease switches off the body’s alarm system, and then ordinary life does the rest. The bacillus itself never touches a fingertip.

Your hands and feet take an extraordinary amount of punishment in an ordinary day, and almost all of the protection is automatic and invisible. You shift your weight before a blister forms. You pull back from a hot pot handle before your brain has finished the word hot. You feel the grit in your shoe at the third step, not the three hundredth.

Take all of that away in a world of open hearth fires, unpaved tracks, wooden tools, no shoes or thin ones, no antibiotics, and no clean water, and the body starts to consume itself through pure accident. A man with anesthetic hands picks up a cooking pot and does not notice that the skin of his palm has cooked. He carries firewood and drives a splinter deep into the base of his thumb and does not find it for a week, by which point the hand is swollen to the wrist and hot to the touch. He walks all day on a foot that has a stone bruise he cannot feel, and the pressure point breaks down into an ulcer, and the ulcer does not hurt.

So he keeps walking on it, and the ulcer works downward through fat and fascia until the bone of the metatarsal is sitting exposed at the bottom of a crater in the sole of his own foot. The medical term is plantar ulceration. In the archaeological record, it turns up as bone that has been remodeled, eroded, and infected, and in the worst cases as feet where the small bones have simply gone. That is the mechanism behind the shortened, tapering fingers and the vanished toes.

Repeated injury, repeated infection, chronic inflammation, and gradual resorption of the phalanges. The body reabsorbing bone it can no longer maintain, so that the digits shorten and the tips draw back, and the fingers end in stumps. Meanwhile, the paralysis of the small muscles of the hand pulls the remaining fingers into a fixed curl, the claw hand, so that even before the flesh goes, the hand no longer opens. Then the secondary organisms arrive.

Ordinary bacteria, the ones that live on everyone’s skin, colonize an open ulcer that never closes. The infection tunnels into the bone, and you get osteomyelitis, which in a body with no antibiotics means a chronically infected bone leaking pus through a sinus tract to the surface. Sometimes the blood supply fails, and the tissue dies outright, blackens and rots on the living body. Gangrene.

And this is where the smell comes from. Medieval writers mention the stench of the leper constantly, and it has been treated as prejudice or metaphor, and some of it certainly was. But a person with three or four chronically infected ulcers, dead tissue in the wounds, sinus tracts draining infected bone, and no way to wash properly is not a metaphor. The face gets it worse than the hands, if anything.

The bacilli colonize the moist lining of the nose and multiply there in enormous numbers. This is almost certainly the main route by which the disease passes from person to person, through nasal droplets, not through touch. The infiltration thickens the mucosa until the nose is permanently blocked and streaming. Then it goes into the cartilage.

The septum, the wall dividing the nostrils, ulcerates and perforates and eventually collapses, and the bridge of the nose sinks in on itself. Saddle nose. And it does not stop at cartilage. The infection attacks the bone of the nasal aperture, widening and eroding the rim, then works into the anterior part of the maxilla, the upper jaw.

The bone of the alveolus, the ridge holding the tooth sockets, thins, becomes pitted and porous, and resorbs. The front upper teeth loosen in their sockets and fall out. Inflammatory pitting runs along the suture in the roof of the mouth, and in advanced cases, the palate perforates, opening a hole between the mouth and the nasal cavity. No nose, a hole in the roof of the mouth, and no front teeth.

Eating becomes messy and humiliating. Fluid comes back through the nose. Speech changes. The same infiltration reaches the larynx, the vocal folds thicken and scar, and the result is a hoarse, nasal, barking sort of voice that medieval examiners specifically listened for as a diagnostic sign.

You could apparently hear an advanced case before you saw them. Then the eyes. Blindness arrives by more than one route. The nerve that closes the eyelid fails, so the lid no longer shuts fully, lagophthalmos, and the eye cannot blink properly or seal at night.

The cornea dries out. The nerve that provides sensation to the cornea also fails, so a scratch or a speck of grit produces no pain and no reflex tearing. Ulcers form on a surface that cannot feel them, and the ulcers scar, and the scars cloud over. On top of that, the bacillus invades the eye directly, producing inflammation inside the anterior chamber, and the iris can become adherent and the pupil sealed.

A man in an advanced state might be sitting in the dark with his eyes wide open, unable to close them at all. For men, the disease often reaches the testes, which are cool enough to suit it. The tissue is destroyed, hormone levels crash, impotence, infertility, and in many cases gynecomastia, the development of breast tissue. Nobody in the 12th century knew about testosterone, but they could see what was happening, and it fed straight into a set of ideas about leprosy and sex and punishment that shaped how these people were handled for the next 400 years.

One more feature of the illness, and patients today describe it as the worst part of the whole thing: leprosy does not grind along at an even rate. It flares. Modern medicine calls these episodes reactions, and they arrive in two main forms. In the first, the immune system abruptly turns on bacilli sitting inside a nerve, and the nerve swells within its own sheath.

High fever, existing patches going red and hot and raised, and a deep boring pain in the arm or the leg as the trapped nerve is crushed by its own inflammation. One episode lasting a few days can finish a nerve permanently. So somebody stable for years can lose the use of a hand inside a week. The second form throws up crops of tender red nodules across the arms, legs, and face, with fever, joint pain, inflamed eyes, and swollen testes.

Both are agonizing, and both recur. Medieval physicians recorded patients with sudden fevers and swellings that came and went, attributed them to a shift in the humors, and treated them by opening a vein in a body that was in the middle of a systemic inflammatory storm. Death, when the disease itself is what kills, tends to come by unglamorous routes. Overwhelming infection from the ulcers.

Septicemia. Kidney failure driven by something called secondary amyloidosis, where the chronic inflammation causes a protein to deposit in the organs until they stop working; at the National Leprosarium in the United States in the 20th century, that was the commonest single cause of death among patients. Tuberculosis, which co-infects an enormous proportion of leprosy sufferers, and often finishes them first. In the Middle Ages, add to that list starvation, exposure, and the ordinary infections of the poor.

None of it is fast. Everything about how these institutions worked follows from that. Somebody could carry this disease for 20 or 30 years, long enough to be diagnosed at 20 and buried at 50. Long enough to spend more of their life inside the leper house than outside it.

Long enough to watch it happen to themselves in stages, in a room with other people at other stages, in a building where your own future sat across the table from you eating bread. How much of this did the medieval world actually understand? Go to Bernard de Gordon. He was teaching medicine at Montpellier, and around 1305 to 1309 he produced a book called the Lilium medicinae, the lily of medicine, which became one of the standard texts of European medical education for the next two centuries.

His section on lepra breaks the disease into three stages, and the accuracy of it is unsettling. In the first stage, the hidden one, before anything is obvious: a reddish, dusky, dirty-looking complexion, the voice beginning to change and coarsen, hair thinning, breath and sweat turning foul, and a melancholic mind full of frightening dreams and nightmares. He is describing the psychological life of a person who does not yet know what is wrong with them but has begun to suspect. In the second stage, what he calls the infallible signs: enlargement of the brows with loss of their hair, the eyes becoming round and staring, the nostrils swollen outside and pinched inside, the nasal voice, the face darkening and taking on a glossy fixed terrible aspect, the wasting of the muscle in the web between thumb and forefinger.

That is a genuinely sophisticated observation; that particular muscle wasting is still taught today as a sign of ulnar nerve involvement and insensibility of the extremities. Then he adds the blood test. Draw blood, wash it, and look at what is left. In a leper, he says, you will find a black earthy sandy residue.

In the third stage, the collapse of the nasal septum, fissures in the hands and feet, the lips grossly enlarged, difficulty breathing, that horse barking voice, and a pulse so small it can barely be found. Then Bernard writes a line that is hard to shake. Sometimes, he says, the limbs drop off piecemeal or entire. He was a professor writing a textbook for students who would be expected to examine these patients and pronounce on them.

He wrote it down because he had seen it. Treatment is the next question, and the answer is that medieval medicine threw everything it had at this disease and got nowhere at enormous cost in suffering. The theory driving it was humoral. Leprosy was understood as a corruption of the blood, usually attributed to burnt or adust black bile, melancholy cooked into something poisonous, sometimes to an excess of heat, sometimes to corrupted seed.

Since the corruption was in the blood, the logical response was to get the blood out. So the mainstay of treatment was phlebotomy, performed repeatedly on a schedule for years. Cut the vein, fill the bowl, do it again next month. Advanced patients were bled from sites chosen according to which part of the body was worst affected, and some regimens called for bleeding several times a season.

On top of that, cupping and scarification, raising blisters or making shallow cuts and drawing blood off through the skin. On a body already anemic from chronic infection, systematically removing blood over a period of years is straightforwardly harmful, and it was the standard of care in every medical school in Europe. Purging came next. Emetics to induce vomiting, and violent laxatives, hellebore, scammony, colocynth, to void the bowels on the reasoning that corrupt matter had to be expelled by some route.

A patient with a perforated palate, no front teeth, and chronic diarrhea from prescribed purgatives is a picture the textbooks do not dwell on. Then the specifics, some of which are memorable. Viper flesh was regarded as one of the genuinely useful remedies, and physicians, including Jordanus de Turre, recommended it. Snake broth, snake powder, snake baked into bread, on the theory that a venomous creature could counter a venomous corruption.

Theriac, the enormously expensive compound electuary containing dozens of ingredients including opium and viper, was prescribed for those who could pay. Gold was administered in various preparations. Mercury and sulfur ointments were rubbed into the skin and the nodules, which achieves nothing against this organism but does produce mercury poisoning. Baths of sulfurous water, ointments of arsenic, cauterization with a heated iron applied to ulcers and to the nerves themselves, sometimes over a course of sessions.

Castration, as with Bishop Hugh of Orival, followed from the corrupted seed theory. Amputation of a limb that had rotted beyond saving was done without anesthesia beyond wine or opium by surgeons who were reasonably good at it and had a survival rate better than you might expect, given that the alternative was gangrene. And bathing in blood. The idea of curing leprosy with human blood, particularly the blood of children or virgins, runs all through medieval writing.

It attaches to the Emperor Constantine in legend. It powers the plot of Amis and Amiloun. And it appears in medical and quasi-medical writing as a remedy discussed rather than dismissed. Dog’s blood turns up, too, both drunk and bathed in.

Freshly killed animals were split open and applied to the body on the reasoning that the heat and moisture of a living creature would draw the corruption out. Puppies and pigeons cut in half and laid on the head. Whether any patient was ever subjected to the full program is unknowable, but the individual pieces are all in the manuals written by serious men for serious use, and somebody paid for them. Guy de Chauliac, who was as good a clinician as the 14th century produced, evidently understood how little of it worked.

The urgency and the near despair that Luke Demaitre noticed in Jordanus de Turre’s treatise on treatment is the sound of a physician who has run out of options and is still writing prescriptions. The one route that offered real hope was the shrine. Miracle collections from across Europe record leprosy cures at the tombs of saints and at holy wells. Canterbury’s water of St.

Thomas among the most famous, with pilgrims drinking a dilution of Becket’s blood and reporting the disappearance of their symptoms. Some of those accounts almost certainly describe people who had been misdiagnosed with a skin condition that resolved on its own. Some describe the milder tuberculoid form, which genuinely can heal without treatment. And some describe people who wanted to be well so badly that they said they were, in front of witnesses at a shrine, and then walked home.

The examination itself is the next thing, and a diagnosis this consequential never happened quietly between a patient and a physician. It happened in front of an audience. The procedure had a name, the judicium leprosorum, the judgment of the lepers, and the earliest formal English examinations we have records of date from around 1227. Who did the examining varied wildly.

Sometimes physicians and surgeons in the university towns and the wealthier cities. Sometimes a bishop or his official. Sometimes the mayor and a panel of town aldermen, men who sold cloth for a living and were now being asked to judge whether your face had changed. Sometimes a jury of ordinary neighbors.

And sometimes a panel made up of existing lepers, on the reasoning that they were the true experts by experience. Men and women with collapsed noses and clawed hands brought out to inspect a frightened person and decide whether that person was now one of them. The other side of that room is worse. You have spent 15 years watching your own body come apart, and now the town brings you a frightened man who still has his eyebrows and asks you to look him over and say the word.

The examination was thorough and it was humiliating. You stripped. Every part of you was inspected, including the parts nobody had inspected since you were an infant. The examiners looked at the earlobes, feeling for nodules along the rim.

They looked into the nostrils with the light behind them, checking whether the septum was intact and whether the lining was thickened. They pulled your hair to see whether it came away in the hand, and they counted the eyebrows. They listened to your voice while making you talk, and they smelled your breath. Then the pin.

The decisive test in most surviving accounts is the test for anesthesia. An examiner would take a needle or a pin and prick a pale patch on the arm or the cheek or the numb-looking area on the leg, and watch the face. Somebody with an ordinary skin complaint, and medieval Europe was full of scabies, psoriasis, eczema, ringworm, vitiligo, syphilis later on, and dozens of other things that produce patches and scales, would flinch. A true leper would not.

Some examiners used a heated instrument instead. Some tested with a cold blade, then a hot one, to see whether the person could tell them apart. The blood tests, which look like nonsense to us, were taken extremely seriously. Draw the blood, let it stand, wash it, and examine the residue for that black granular sand Bernard described.

Mix it with water and see whether the water clouded. Mix it with salt and see whether the mixture behaved oddly. Sprinkle it on a hot iron and smell the smoke. Look at the urine.

Take the pulse. It was a whole apparatus of examination applied with real seriousness in the service of a judgment that would end a life as that person had known it. Jordanus de Turre, another Montpellier man, active roughly between 1313 and 1335, wrote up the whole diagnostic battery in a short treatise on the signs of leprosy that circulated so widely it often traveled under the name of Arnold of Villanova. His companion piece on treatment, which the historian Luke Demaitre examined in a 1996 article in the Bulletin of the History of Medicine, carries an air of urgency and something close to futility.

You can hear a working physician in it. He knows what he is looking at. He knows roughly where it ends, and he is still going to prescribe something. And the best surgeon of the age put his finger on exactly the problem with all of it.

Guy de Chauliac finished his Chirurgia Magna in 1363, having served three popes at Avignon, and having stayed in that city through the Black Death when most of the physicians fled. On leprosy, he warns his colleagues to be extremely careful, because the injury done by segregating someone who should not be segregated is very great. And so is the injury of leaving a true leper walking among the people. He is caught between two harms, and he says so.

He was right to worry. The wrongly condemned turn up in the records, and their panic comes through the archive. A physician named Amonant moved from Gascony into Aragon, and in 1322 was seized at Huesca as a leper and a poisoner, which in that particular year was a combination that could get you burned. He appealed to the king’s son, Alfons.

Local physicians examined him and found no sign of the disease. He was let go, and he immediately fled the kingdom, which tells you how confident he felt about the verdict holding. Somewhere between 1487 and 1507, a man called Jahan Jacquemin wrote to the Duke of Lorraine begging him to intervene and get his leprosy diagnosis overturned. We have his letter.

We do not know how it ended. And the diagnosis could be used as a weapon. A woman called Alice Dymock is the case for that. She lived in Great Yarmouth and she appears in the town court records repeatedly and colorfully.

Thief, procuress, adulteress, scold, seller of unlicensed ale. The authorities finally got rid of her by presenting her as a leper, which forced her out of the town. Her response was to take revenge by going round at night milking her neighbors’ cows. Carole Rawcliffe recovered that story, and it says something about how the mechanism worked in practice.

If a community wanted somebody gone, here was a procedure that could make them gone with the full weight of law and religion behind it, and no appeal that most people could afford. One more, and this one is quietly devastating. A surviving agreement records a man named Elianus and his son submitting themselves to examination by a town council on terms. If they were found leprous, they would pay the examiners’ costs.

If not, the town would reimburse them. Elianus eventually admitted his leprosy. The sense of the document is that he did it to spare his son the inspection, to stop them stripping the boy and pricking him with pins in front of the aldermen. He was moved out to outbuildings beside the Jewish cemetery, and then to a nearby castle.

Once the judgment came down, what happened next depended enormously on where you were, and one ceremony above all others has shaped how the whole subject comes down to us: the mass of separation, separatia leprosorum. The idea of legally isolating lepers is old in European law. The Lombard king Rothari devoted a chapter of his great edict in 643 to lepers, and Charlemagne’s decrees carried similar provisions. By the High Middle Ages, the principle had been absorbed into custom and church practice from Sicily to Norway.

What varied was the ritual dressing. In the fullest surviving forms of the ceremony, and versions turn up in the Sarum manual in England and in a range of continental pontificals, the newly diagnosed person was brought into a church and treated deliberately and explicitly like a corpse. In some variants, they knelt or lay beneath a black cloth. The priest recited the service.

Then he took a spade of earth from the churchyard, or a handful, and cast it over the person, onto the feet in most versions, onto the head in others, while pronouncing the formula: “Be dead to the world, live again to God. ” Sis mortuus mundo, vivens iterum Deo. A living man standing in a church with graveyard soil on his shoes. Then came the prohibitions, and they survive as a concrete, itemized list.

The specificity is the cruelty. I forbid you ever to enter a church, a monastery, a fair, a mill, a market, or any assembly of people. I forbid you to leave your house unless dressed in your leper’s habit. I forbid you to wash your hands or anything belonging to you in a stream or a fountain, or to drink from one except with your own vessel.

I forbid you to enter a tavern. I forbid you, if you meet anyone on the road, to answer them until you have moved so the wind carries your breath away from them. I forbid you to go down a narrow lane in case you brush against someone. I forbid you to touch a child or to give anything to a child.

I forbid you to eat or drink in any company except the company of other lepers. I forbid you to touch the rim of a well or the rope without your gloves on. Take that list as a set of instructions for how to move through a village for the rest of your life. No inns, no markets, no mills, which in a grain economy means no way to process your own food.

No church, though some versions permit attendance at a separate window or a leper’s squint cut into the wall. No conversation without first checking which way the wind is blowing. No touching a rope that a child might touch tomorrow. And that last clause about gloves gives away something important about how they understood the disease.

They did not have a germ theory, but they had a working model of contagion that was specific enough to distinguish between touching a well rope bare-handed and touching it with a glove on. Somebody had worked out that hands carried it, and was trying to solve a public health problem with the tools available. The version of this ceremony that has come down through popular history is more extreme still. In that version, the leper is declared legally dead.

A funeral mass is sung over him. He stands in an open grave while the earth is thrown. And from that moment, he has no legal existence whatsoever. His property passes to his heirs.

His marriage is dissolved. He is a walking ghost with a bell. The evidence for how far any of that actually happened pulls in several directions at once. On one side, the great English jurist Henry de Bracton, writing around 1235, held that lepers, like the insane, could not bring a suit in court, could not inherit, and could not make contracts.

Later writers summarized that as civil death, and the phrase stuck. The Catholic Encyclopedia states flatly that lepers were excluded from the church by a funeral mass and a symbolic burial, citing the liturgical scholar Martène, who was working from manuscript service books. Those service books exist. Somebody wrote those words down for use.

On the other side sits the practical record of what lepers were actually doing. The historian Françoise Berriac worked through the documents of southern France and found lepers making contracts, selling land, and writing wills exactly as healthy people did. Elma Brenner’s work on Rouen shows the lepers of that city active in the property market, buying, leasing, and holding. In England, the writ that supposedly enabled the forced removal of lepers from a town, de leproso amovendo, is, according to Rawcliffe’s work, absent from the English legal texts until a reference in 1531, very late indeed for a mechanism that is usually described as characteristic of the High Middle Ages.

The removals we can actually document earlier than that tend to involve specific individuals who were being difficult, provocative, or dangerous, or sweeps aimed at vagrants and prostitutes, and they cluster in plague years when everyone was frightened of everything. The church’s own formal position sits between the two, and it is more interesting than either extreme. The Third Lateran Council in 1179 addressed the question directly in its 23rd canon. “Because lepers cannot live with the healthy or come to church with others,” it says, “they should be permitted their own churches, their own cemeteries, and their own priests wherever enough of them live together to form a community.

” That canon assumes separation and, in the same breath, guarantees the separated person a church, a burial ground, and the sacraments. It is a document that takes the leper out of the parish and simultaneously insists that the leper remains a Christian with a soul and a right to be buried in consecrated ground. Both things were happening. A liturgy of symbolic death existed in some places and was performed in some places.

And in other places, a man diagnosed on Tuesday was arguing about a land lease on Thursday. Medieval Europe was not a single system with a single rulebook. It was thousands of towns and hundreds of dioceses improvising, and the improvisations ranged from the tender to the murderous, sometimes in the same decade, sometimes within a day’s ride of each other. So, what did a person actually walk into once the ceremony was over and the gate closed behind them?

The popular image of the leper house is a shed full of dying wretches. The surviving account books describe something closer to a small monastery with a very specific admissions policy, and the food records are where that becomes impossible to ignore. Take Sherburn, near Durham. It was founded in 1181 by Bishop Hugh de Puiset, Bishop Pudsey, as the Durham records tend to call him, to house 65 lepers, and dedicated to the Blessed Virgin, along with Lazarus and his sisters Mary and Martha.

Sixty-five is a substantial number. A house that size needs a kitchen, a brewhouse, a chapel, a cemetery, staff, and a supply chain. And the foundation ordinance sets out the diet in almost obsessive detail. Every inmate received daily a loaf of bread weighing five marks and a gallon of ale.

On three days of the week, a mess of meat shared between every two people. On the other four days, fish, cheese, and butter. On the great feasts, and especially on the feast of Saint Cuthbert, a double portion. On Michaelmas Day, four of them shared a goose.

In Lent, when meat was forbidden, they were to have fresh salmon when salmon could be got, and other fresh fish when it could not. If fresh fish failed entirely, then three red herrings between every two people, or cheese and butter measured out by weight, or three eggs each. Every Lent brought a razer of wheat for frumenty, that is, a sweet wheat porridge boiled slowly in milk, and two razers of beans for boiling, and sometimes greens or onions. Red herring was specifically prohibited between Pentecost and Michaelmas, a rule written by somebody who had smelled a barrel of summer herring and made a decision about it.

At Michaelmas, two razers of apples each. The house maintained a common kitchen with a paid cook, and the inventory lists the equipment. A great boiling vessel, two brazen pots, a laver for washing, and vats for ale and for bathing. Bathing vats.

That is a detail that runs directly against everything we tend to assume. The sick, meaning those who had deteriorated past the point of getting about, were to be given fire and candles and all necessaries until they either recovered or died. And each inmate had an annual clothing allowance. Three yards of woolen cloth, white or russet, six yards of linen, and six yards of canvas.

Compare that with a peasant family in a bad harvest year in the same county, and the leper at Sherburn is doing better. Bread and a gallon of ale a day, meat three times a week, a goose at Michaelmas, apples, a fire when you are dying, and clean linen once a year. The Hospital of Saint Julian at St. Albans records something similar in the 14th century, around 1335 to 1349.

Each leprous brother got seven loaves a week, five white, two brown, and 14 gallons of beer or eightpence in place of it, 40 gallons of good beer at Christmas, two quarters of corn as what the document calls the great charity, a pig from the common stall at Martinmas, chosen in order of seniority, which means the longest surviving lepers picked their pig first, and the newcomers took what was left. A quarter of oats at Candlemas, two bushels of salt at the Feast of Saint John the Baptist, 4 shillings a year for clothes, and 14 shillings divided among the brothers for the year’s fuel. Set the beer and the pig and the fire against what was physically happening to these same bodies at the same time. Both are true at once, and the combination is worse than either half on its own.

A man at Sherburn in 1230 could be eating better than his brother in the village, while his own foot rotted off in the bed. Well-fed and disintegrating. Warm, dry, fed, and blind, with a hole through the roof of his mouth and a hand that would not open. The charity was real.

It also could not touch the disease by so much as a day. And the food came with conditions attached. Most houses confined their inmates within a set boundary, often around a mile, and forbade them from staying out overnight. Many barred them from the bakehouse, the brewhouse, and the granary, on the stated reasoning that it was unfitting for persons with such a malady to handle food intended for common use.

So the men and women being fed by the institution were forbidden to touch the institution’s grain. Some houses had a gallows standing in front of the gate for those who broke the rules badly enough. A hospital founded in charity, dedicated to the Virgin, with a gallows at the entrance. Celibacy was the standing rule, and it was enforced.

Sexual transgression meant expulsion, and expulsion from a leper house in the 14th century meant the road, the clapper, and whatever the weather did to you. Married couples were sometimes admitted together, and then required to live apart. Given what we know about the disease’s effect on fertility and function in advanced cases, some of these rules were policing something that had already been taken away, and the rules stayed on the books anyway. The distinctive dress and the warning instrument were the other daily conditions.

The clapper, a wooden rattle, two or three boards hinged so they slapped together when shaken, or a bell, depending on the region and the century. That sound was the leper’s public identity. You heard it before you saw the person, which was the entire design intention. Some houses obtained a royal license for a specific brother to go out and beg on behalf of the whole community, as at St.

Mary Magdalene’s at Beccles in Suffolk, and that man became the house’s public face, standing at a crossroads or a bridge with a box, shaking a rattle so that everybody within earshot knew what was coming and could decide whether to cross the road or reach for a coin. The dress rules were precise in some towns and vague in others. A gray or russet gown closed at the neck with a hood, gloves, in a number of continental towns, a mark stitched to the breast or the shoulder. Some places specified boots or wooden clogs.

Legibility at a distance was the whole purpose of the costume. Surviving examples in museum cases are plain hinged boards of oak or beech, small enough to be worked by a fist that no longer opens properly, and they make a dry knocking sound that carries a long way in still air. Begging with one meant standing at a fixed spot, a bridgehead, a gate, a crossroads beside a church, for hours at a stretch, shaking a board to attract precisely the attention everybody else had been trained to avoid. Coins went into a box or a bowl fixed to the end of a pole or onto a stone so that no hand ever touched another hand.

Over in Normandy, the record is detailed enough to show that these places were not uniform in temperament. Elma Brenner’s work on Rouen turns up the ordinances of 1249 for the leprosarium of Salle-aux-Malades just outside the city, and one clause permits the residents to choose for themselves whether or not to undergo bloodletting. That is a small clause and an enormous one. Somebody sat down and wrote a rule giving diseased inmates the right to refuse a medical procedure.

Meanwhile, the great Rouen house at Mont-aux-Malades, founded in the first third of the 12th century, was patronized by Henry II, and its prior, a man called Nicholas, was a personal friend of Thomas Becket. After Becket’s murder and canonization, the church there was rededicated to him. Kings and archbishops had their hands directly on these institutions. In political terms, these houses sat close to the center of things.

But the money is where it goes wrong, and it goes wrong with total predictability. A leper house was an endowed corporation. It had land, rents, tithes, mills, and legacies. It had a master or a prior who controlled the income.

And the people it existed to serve were diseased, poor, often illiterate, frequently blind, and legally awkward. That is an arrangement that invites theft, and theft is what the records show. The Royal Leper Hospital of St. Giles at Holborn in London has a long and grubby history of being stripped of its assets.

In 1348, the citizens of London complained to the king that since the master and brothers of Burton Lazars had taken the place over, the healthy brothers of the Order of St. Lazarus had pushed out the actual lepers and installed themselves in their places. Put that in plain terms: a religious order dedicated to the care of lepers, evicting lepers from a leper hospital so its own members could enjoy the endowment. The 14th century produced repeated accusations of corruption there.

At St. Giles’s Leper Hospital in Shrewsbury, first recorded in 1155, alleged breaches of the foundation charter triggered a royal inquiry in that same year of 1348. The corody is the mechanism by which the whole system quietly rotted from the inside. A corody was a lifetime maintenance contract.

You paid a lump sum, and the house fed and housed you until you died. For a hospital short of cash, selling corrodies was easy money. For a comfortable townsman worried about his old age, it was a pension. The effect, over a century or two, was that beds founded for destitute lepers filled up with paying pensioners who were healthier and richer, and the sick poor were squeezed out to the margins of the very institutions built for them.

By the later Middle Ages, several English leper houses had almost no lepers in them at all. The whole apparatus ran on charity, and charity in the medieval sense was an industry with its own machinery and its own fraud. Bequests in wills, sometimes very large. Richard Whittington, the real man behind the pantomime, left money to London’s leper houses.

Indulgences offered to those who gave alms to lepers, which converted a coin into a reduction of time in purgatory. The leper’s box at the gate, or carried by a licensed beggar. Proctors and questers traveling the countryside collecting on behalf of a named house, carrying sealed letters of authority. And inevitably, forged letters of authority carried by men with no house behind them at all, and stories of collectors keeping the money.

The numbers give the scale of it. Rotha Mary Clay’s classic survey, The Medieval Hospitals of England, published in 1909, and the work that has followed her, establishes a bare minimum of around 320 leper houses in England by 1350. The great majority of them founded before the 14th century. Three hundred and twenty in a country whose population was perhaps four or five million before the plague.

Matthew Paris, writing in the 13th century, put a rough figure of 19,000 leper houses across Europe, with something like 2,000 in France alone. His numbers are a chronicler’s guess and should be handled as such, but even discounted heavily, they describe a continent covered in these institutions, one on the edge of nearly every town of any size, usually beside a road, usually near a crossroads or a bridge or a gate, positioned exactly where travelers would pass and coins might be extracted. That siting was deliberate, and it had a double logic. Outside the walls, so the diseased were not among the healthy.

Beside the road, so the diseased could beg. The architecture of exclusion and the architecture of fundraising were the same building. Clay also traced the shape of the epidemic itself, and her outline still broadly holds. Leprosy raged in England from the 11th century through to the middle of the 13th, began to slacken after that, was already inconsiderable by the middle of the 14th, and had practically vanished by the 16th, except in pockets in the far southwest.

Two and a half centuries of a slow disfiguring disease at high prevalence, then a fade. Why it faded is still an open question, and the answer coming out of the DNA has surprised nearly everyone working on it. Before the DNA, though, the bones. Most of the physical evidence for all of this comes out of the ground rather than out of chronicles or sermons, and it comes in enormous quantities.

The single largest English assemblage is from Chichester in West Sussex, where the cemetery of the Hospital of St. James and St. Mary Magdalene was excavated in 1986 and 1987 and again in 1993, and published by John Magilton, Francis Lee, and Anthea Boylston in 2008 under a title that has stayed with me, Leapers Outside the Gate. Almost 400 skeletons.

The largest sample from an English medieval leper hospital, and one of the most significant leprosy assemblages anywhere in Europe. The institution began in the 12th century as a men’s house, later took in women and children, and survived the Reformation by quietly reinventing itself as an almshouse for the sick poor. About 19. 5 percent of the Chichester individuals show skeletal changes from leprosy, a long way from the 85 percent at Winchester, and the gap has a straightforward explanation.

Leprosy only reaches the bone in a minority of infections and only after years. Many people died with the disease in their soft tissues and nothing whatsoever in their skeletons. And beyond that, houses like Chichester were admitting the disfigured, the chronically sick, and the destitute in general, not confirmed lepers alone. St.

John’s at Timber Hill in Norwich comes out at 19. 4 percent, almost the same figure. Winchester’s northern cemetery at over 85 percent looks like a place that was taking in confirmed cases and very little else, at least in that phase. The Chichester bones carry something else, though, and it is the clearest physical proof of what anesthesia does to a human being over years.

Sherry Judd examined 212 sexed adults from the cemetery and published the results in the American Journal of Physical Anthropology in 1998. The long bone fracture rate was 15. 1 percent. In comparable medieval populations that were not hospital populations, the figure runs between about 3.

3 and 5. 6 percent. So, three times the fractures. Men accounted for 85.

4 percent of them, and leprous bone changes were present in 28 percent of the individuals who had broken a bone. Broken arms and legs over and over in a population that could not feel its own limbs properly, could not see well, could not grip, and was walking on ulcerated feet. Every one of those fractures happened to somebody in a yard or on a stair or on a track, and then had to knit itself back together without a splint that anyone was going to bother setting properly. Several of the Chichester breaks healed badly out of alignment, which means the person walked crooked afterwards on legs they could not feel.

The foundational work on all of this happened in Denmark, and the man who did it deserves his name said out loud. Vilhelm Møller-Christensen excavated the cemetery of the Saint Jørgens Leprosarium at Næstved and published Ten Lepers from Næstved in Denmark in 1953. From that material he identified and defined the specific facial bone changes of the disease. He called it facies leprosa, the leprous face, later formalized by Andersen and Manchester in 1992 as rhinomaxillary syndrome.

The components of that syndrome are what we described earlier, seen from the inside. Erosion and remodeling of the margins of the nasal aperture, so the nose hole in the skull widens and its edges become ragged. Loss of the anterior nasal spine, the little bony point at the base of the nose. Destruction of the thin bones inside the nasal cavity.

Inflammatory pitting running along the suture in the middle of the hard palate, which in advanced cases eats straight through and leaves a perforation. And resorption of the alveolar bone of the upper jaw, so the sockets of the front teeth shallow out and the incisors are lost. A skull in that condition is unmistakable on a laboratory bench. The face has been hollowed out from the inside.

Møller-Christensen and his collaborators found something else in the Danish material, and it is the ugliest thing in the whole of the Danish material. Danielsen described it in 1968, leprotic odontodysplasia. In four children from Næstved aged between eight and 11, the roots of the permanent upper front teeth were malformed and stunted because the disease had interfered with the teeth while they were still forming inside the jaw. The worst was burial 404, a child of eight or nine whose upper incisor roots ended in blunt little apical buds two to three millimeters long.

So that child was infected in early childhood, years before death, and the infection was severe enough to derail the development of permanent teeth that had not yet erupted. Møller-Christensen concluded from the Næstved series as a whole that most sufferers caught it in childhood. Small children in crowded houses, from the adults they slept beside, at four or five or six years old, with the incubation ticking quietly away through the whole of their childhood. The Danish evidence has expanded enormously since then.

The Saint Jørgens Leprosarium cemetery at Odense, in use from the 13th century into the 16th or 17th, was excavated in 1980 and 1981 and produced more than 1,200 individuals, now curated in the anthropological database at the University of Southern Denmark. From that collection, Matos worked with 191 skulls with well-preserved maxillary regions. Forty-three of them belonging to people under 20 years old at death. Forty-three individuals under 20 from one cemetery, from one hospital.

And the chemistry of the Danish bones has produced a result that quietly undercuts the cheerful picture painted by those foundation charters. Brusoe and colleagues, publishing in 2019 and 2021, analyzed carbon, nitrogen, and sulfur isotopes in bones with different turnover rates, which lets you see diet at different points in a person’s life, for 31 individuals from Næstved and 100 from Odense. What came back was a predominantly terrestrial diet, plants and land animals, with only minimal input from marine or freshwater fish. In a country with that coastline, at institutions whose statutes specify fish rations on four days a week and through the whole of Lent, only six of the Næstved individuals showed evidence of having eaten large amounts of freshwater fish.

Whatever the foundation charters promised, the bodies in the ground had not eaten it, or only some of them had, which raises the possibility of a hierarchy inside these houses, with the fish and the good bread going to the paying residents and the founders’ kin, and the porridge going to everybody else. The corody problem, written into bone chemistry. Excavated leper cemeteries turn up right across Europe once you start looking. The Sant Llatzer leprosarium in Barcelona, running from the 12th century all the way to the 18th.

A leprosarium near Beja in Portugal with seven skeletons exhumed near the Ermida de Santo André. Substantial Hungarian material, including some of the oldest cases on the continent, and at least one cemetery directly tied to a documented leprosarium, worked on by Pálfi and colleagues. Material from Croatia. Cases from Sigtuna in Sweden.

The disease was continental, and it lasted for centuries. In the last 15 years, the bones have started to talk in a way nobody expected. In 2013, a team including Verena Schuenemann, Johannes Krause, Stewart Cole, Pushpinder Singh, and Ben Krause-Kyora published a paper in Science with the flat title “Genome-Wide Comparison of Medieval and Modern Mycobacterium leprae. ” They had pulled bacterial DNA out of five medieval skeletons from Britain, Sweden, and Denmark.

In one of those skeletons, the preservation was so extraordinary that they were able to assemble the entire ancient bacterial genome from scratch, without using a modern sequence as a scaffold at all. That has almost never been possible with an ancient pathogen. The reason it worked here is grim and simple. An advanced lepromatous case carries such colossal numbers of bacilli in the tissue that the bones are effectively saturated with them.

And when they compared those medieval genomes with modern strains, the result was that the bacterium had barely changed. A thousand years, and the genome was almost identical, with no loss of virulence along the way. The organism that vanished from medieval Europe was the same organism that infects 200,000 people a year today. Cole put the implication about as bluntly as a scientist can.

If the explanation for the disease’s disappearance is not in the pathogen, then it is in us. That points toward human genetic resistance. The horrifying possibility that Europe stopped having leprosy in part because the people most vulnerable to it were segregated, prevented from marrying, prevented from reproducing, and buried in separate ground for 250 years while everyone else went on having children. Natural selection running through the leper houses.

A follow-up paper in 2018 in PLOS Pathogens complicated the picture further by showing that medieval Europe already contained a surprising diversity of M. leprae strains, including lineages that today are found on other continents entirely. So the traffic in this disease may well have run outward from Europe as much as inward, with the pilgrim ships and crusading armies and trading fleets carrying it away as readily as they brought it home. The Winchester material sits right at the center of that work.

One individual from the site, cataloged as skeleton 14, produced a complete genome that grouped firmly with the 2F strains. And its closest relative anywhere in the global family tree of the bacterium turned out to be another skeleton from the same cemetery. Same hospital, same decades, same strain passing between people living in close quarters. An outbreak visible in molecular detail 900 years after it burned out.

And one more Winchester burial, published in 2022 by Cole, Taylor, Stewart, and Dawson-Hobbs, carried confirmed lepromatous leprosy of the 3I lineage together with an osteosarcoma, a bone cancer growing in the tibia and fibula, a malignant tumor swelling the shin of a person who was already blind and mutilated by leprosy, and who could not feel the leg it was destroying. Understanding why medieval Europe treated these people the way it did means going into the theology, and the theology is not a single position. It is two positions held simultaneously by the same people. And the contradiction was never resolved because nobody needed it resolved.

Start with the scriptural foundation, built on a translation problem that nobody in the Middle Ages knew was a translation problem. Leviticus chapters 13 and 14 contains a long and detailed set of rules about a condition called tsara’ath in Hebrew. The priest inspects the affected person, examines the hair in the patch and the depth of the sore, isolates them for seven days, inspects again, and pronounces them clean or unclean. Crucially, tsara’ath in Leviticus also affects garments and the walls of houses.

You can have tsara’ath in a woolen cloak or in the plaster of a wall, and the priest inspects those, too. If it persists, the cloak is burned and the stones of the house are torn out and carried to an unclean place outside the town. A disease of walls is not Hansen’s disease. Whatever tsara’ath described, and various 19th-century physicians proposed psoriasis, favus, vitiligo, and several other conditions, the Levitical category covers surfaces and ritual impurity rather than a bacterial infection of the peripheral nerves.

But when those chapters went into Greek, and then into the Latin of the Vulgate, tsara’ath became lepra. And lepra was the word medieval Europe used for the disease we have been describing. So a body of purity law about scaly patches on cloth and plaster arrived in 12th-century Europe as divine legislation governing exactly what should be done with a man whose nose had collapsed. The isolation, the inspection by a religious authority, the pronouncement of unclean, the removal outside the settlement, all of it was in the text, apparently commanded by God, waiting to be applied.

On top of that came the punishment stories. Miriam, struck with tsara’ath for speaking against Moses. Gehazi, the servant of Elisha, struck for greed. King Uzziah, struck in the temple for presumption and living out his days in isolation.

Three biblical cases in which the condition arrives as direct divine retribution for a specific sin, all of them well-known, all of them preached on. So a leper had done something. And the something in the medieval mind was almost always sexual. The associations were dense and physical.

Loss of the nose was a recognized judicial punishment for certain crimes and a recognized mark of the sexual offender in several European legal traditions. So a man whose nose had rotted away wore what looked like a court sentence on his face. The swelling of the lips, the coarsening of the skin, the hoarse voice, and in men the enlargement of breast tissue and the failure of the genitals, were interpreted as the visible aftermath of a body burned out by lust. The disease was thought to be transmitted by sexual contact, which it is not, or at least not meaningfully.

And lepers were cast as creatures consumed by an appetite that had destroyed them and would destroy anyone who came near. The 12th-century Tristan tradition gives that fantasy a voice. In Beroul’s version, when Iseult is condemned, a leper called Yvain steps forward and asks for her to be handed over to his company of lepers instead of being burned. And he describes what awaits her in terms designed to be worse than the fire.

He boasts of an appetite no woman could survive, of the rags and the sores, of the hut on the ground where she would be shared among them. Mark hands her over. She is walked away toward the leper camp. And the audience for that poem understood the exchange perfectly.

Burning was the merciful option. Running alongside all of that was one of the most persistent and destructive beliefs of the whole period: that a child conceived at the wrong time would be born leprous. Conception during the mother’s menstruation was the classic version, but the list expanded to include the forbidden days of the church calendar, holy days, Sundays, times of fasting. So when a child of eight or nine appeared with the disease already destroying the roots of their unerupted teeth, the explanation on offer was that the parents had done something filthy on a feast day.

That child at Næstved, burial 404, would have been looked at that way. And the medieval mind refuses to stay in the box we build for it, because the exact same religious culture produced the exact opposite conclusion. In that second version, the leper is one of the chosen, somebody undergoing purgatory here on Earth, having their sins burned off in the flesh while still alive, and therefore assured of going directly to God at death without the intervening centuries of purgatorial fire that awaited everyone else. The suffering counted as evidence of favor.

Gregory of Nazianzus, back in the 4th century, called leprosy a sacred malady. The Bishop of Tournai in 1239 described it as a gift from God. Saint Hugh of Lincoln, who lived from around 1135 to 1200, treated the leper’s condition as a purgatorial hardship comparable to Christ’s own passion, and made a point of physical contact with lepers in a way that shocked his own household. And the deepest root of that idea sits in Isaiah 53, where the suffering servant is described as smitten of God and afflicted, despised and rejected, a man from whom people hid their faces.

Medieval commentators applied that passage to Christ, and then noticed that the description fitted the leper on the road outside the gate. Some texts go as far as calling Christ himself leprous. So the man with the clapper might be a walking punishment or a walking crucifix. And which one he was depended on who was looking at him that morning.

The patron of the whole thing was Lazarus, and even that comes with a tangle. The Lazarus of the parable is the beggar covered in sores who lies at the rich man’s gate, licked by dogs, and is carried by angels to Abraham’s bosom while the rich man goes to torment. A separate Lazarus, Lazarus of Bethany, is the man Christ raised from the tomb. Medieval devotion fused the two, and the fusion was theologically perfect for this purpose.

The sore-covered beggar, who is also the man who came out of the grave, a dead man walking who ends up in heaven. Leper houses across Europe took his name, and the English word for them followed. Lazar house, lazaret, lazaretto, a word that ended up attached to plague quarantine stations centuries later. The Order of Saint Lazarus was founded in the 1140s in Jerusalem specifically to care for lepers, and it did something remarkable.

It admitted leprous knights, and by tradition its master was himself a leper. Crusader knights who contracted the disease in the East could transfer into the order and go on fighting. Its English headquarters was at Burton Lazars near Melton Mowbray in Leicestershire, and the order held property across the country, including the mastership of Saint Giles at Holborn, and that is how it ended up at the center of the eviction scandal we looked at earlier. Leprous knights are a strange thing to sit with.

Men with no feeling in their hands holding weapons. Men going into a melee without the ability to feel a wound. Whatever else was true of them, they were not people with much left to lose. The saints are the other half of it.

Francis of Assisi put the moment in his own testament near the end of his life, in language that does not flatter him. When he was still in his sins, he says, the sight of lepers was so bitter to him that he could not bear it. He was nauseated beyond measure. Then God himself brought him among them, he says, and he had mercy on them.

The tradition from the earliest biographies places the turning point on a road near Assisi where he came upon a leper, dismounted, and kissed him. Every biography of Francis has to handle that scene, and it works as the founding gesture of his entire movement on the strength of what his audience already knew a leper looked and smelled like at close range. The kiss is only remarkable if you know what was under his mouth. Elizabeth of Hungary nursed lepers with her own hands, and was the subject of a story, probably later, probably devotional, in which she puts a leper into her husband’s bed, and he pulls back the covers to find Christ lying there.

Louis IX of France was said to have washed and tended lepers personally, which for a reigning king is a considerable statement. Bartolo of San Gimignano spent the last 20 years of his life among leprosy patients, having contracted the disease himself, and was known as the Job of Tuscany. Queen Radegund attached herself to the same work centuries earlier. And Alice of Schaerbeek, Alice the leper, is the case where both versions collide in a single life.

She was born around 1220, entered the Cistercian Abbey of La Cambre near Brussels as a lay sister as a young girl, and contracted leprosy. She was removed from the community and confined to a separate cell. Her sight went. She lost the use of her limbs.

Her hagiography states that she was denied the communion wine on the grounds of contagion, and grieved over it. And that Christ appeared to reassure her that she had received him whole. She died around 1250, at roughly 30 years old. And she is venerated as a patron of the blind and the paralyzed.

A nun expelled from her own convent because of her body, and canonized for what her body did to her. The single most extraordinary leper of the Middle Ages, though, was a king. And he was never hidden away for a day of his life. Baldwin IV ruled the kingdom of Jerusalem from 1174 until his death in 1185.

His tutor was William of Tyre, one of the finest chroniclers of the entire medieval period. And William tells us exactly how the disease was noticed. Baldwin was about nine, playing with the other boys of the court. The game involved pinching and digging fingernails into each other’s arms.

Ordinary rough play. The other boys yelped. Baldwin did not. He felt nothing in his right arm.

And he did not react at all. And William, watching, understood that this was not toughness. That is the anesthesia we described earlier, appearing in a child at play in front of a man educated enough to know what it meant. William writes about it with visible grief.

He had taught the boy. He liked him. And he understood that the kingdom’s heir was going to come apart in public. The disease progressed into the lepromatous form, the worst outcome available.

Over the following decade, Baldwin developed ulceration, facial change, and the loss of function in his hands and feet. By around 1182, William records that his sight was failing and his extremities were so deadened that his hands and feet refused to do their work. He could not hold a sword. He could not properly sit a horse.

He was going blind. He was in his early 20s. He kept commanding armies anyway. In November of 1177, at the age of about 16, with the disease already established, Baldwin faced Saladin at Montgisard with a badly outnumbered force.

He was there in person. The account has him carried or helped, and the Frankish charge broke Saladin’s army so thoroughly that the sultan barely escaped the field. That is a teenager with numb hands winning the most celebrated Frankish victory of that generation. Afterwards, as the disease advanced, he had himself carried on a litter to councils and to campaigns.

He appeared before his own barons blind, with a face they could not look at directly, with hands bandaged, and gave orders. He presided over succession disputes and the arrangements for the kingdom after his death, which he knew was coming and knew was coming soon. When he could no longer function at all, he arranged the crowning of his young nephew. He died in 1185 at about 23 or 24 years old.

Two years after that, the kingdom he had held together lost the field at Hattin, and Jerusalem fell. The ordinary logistics of Baldwin are what stays with you. Somebody dressed him. Somebody cleaned and bandaged the ulcers on his hands every morning and dealt with what came off.

Somebody carried him. Somebody stood beside him at councils and told him quietly who was in the room because he could not see them. A whole apparatus of people existed around the daily maintenance of a rotting king, and not one of them wrote down what it was like. Voices from inside the disease are almost nonexistent, which makes the exceptions precious.

Jean Bodel of Arras was a poet and playwright, a genuinely accomplished one, and in 1202 he was diagnosed. He was preparing to go on crusade. Instead, he went into a leprosarium, and before he did, he wrote a farewell poem, a congé, addressed to his friends in the town. He tells them that reason commands him to take up a penitent life.

He also tells them, without much decoration, that the shame and the torment of it are driving him out of his mind. He lived another eight years in the house and died there. Bishop Hugh of Orival of London, who died in 1085, was a leper. He underwent castration as a treatment for the disease, a treatment based on the theory that the condition arose from an excess of corrupted seed and heat.

Removing the source would remove the cause. It did not. And the contemporary comment on him is revealing. The mockery he suffered was for the castration, rather than for the disease.

A bishop with a collapsing face was tolerable. A bishop who had been cut was a joke. A carved stone head survives from Melton Mowbray, near the preceptory at Burton Lazars, showing a face with what appear to be the changes of advanced leprosy. David Marcombe and Keith Manchester examined it in Medical History in 1990, combining the historical and the medical evidence.

Somebody carved that face deliberately in stone, in a place run by the Order of Leper Knights, and left it on a building. Whatever it meant, it was not meant to be hidden. Everything we have covered so far, the ceremonies, the rations, the gallows at the gate, the ambivalence, describes a system that was cruel in its ordinary operation, but not in the main homicidal. It could support you for 30 years while your body failed.

It could also, in the space of about four months, decide to burn you alive. The year was 1321, and the place was France. The ground had been prepared the summer before. In 1320, an unauthorized movement of young men and boys, the so-called Shepherd’s Crusade, swept up through the southwest of France with the stated aim of going to fight in Spain and the Holy Land, and instead spent its energy massacring Jewish communities as it went.

Bordeaux, Toulouse, and dozens of smaller places. In Verdun-sur-Garonne, according to the accounts, a group of Jews took refuge in a tower, held out, and killed themselves rather than be taken. The movement was eventually broken up by royal officials, but it had established something: that a wave of popular violence against a marginal group could roll across an entire region before the crown got round to stopping it, and that the men who joined it would not be punished much. The following spring, a rumor began circulating in the same region.

Lepers, it was said, were poisoning the wells. Not in a general way. The rumor was extremely specific, as these things tend to be. Powders made from a recipe containing human blood, urine, three unnamed herbs, and a consecrated host.

That last detail turning the crime into sacrilege as well as murder. The powders were to be wrapped in cloth and weighted with a stone, and dropped into wells, fountains, rivers, and springs, so that everybody who drank would contract leprosy. And the purpose, in the fully developed version, was that the healthy would become leprous, and the leprous would then take their places, inheriting their lands and their lordships. Bernard Gui was the inquisitor at Toulouse.

He was present at many of the interrogations, and he wrote about it afterwards. In his account, an evil plan by the lepers against the healthy people of the kingdom of France was detected and prevented. “Persons unhealthy in body and insane in mind,” he writes, “had arranged to infect the waters of the rivers and fountains and wells everywhere by placing poison and infected matter in them, and by mixing prepared powders. ” That is one of the most experienced inquisitors in Europe, a man who had written the manual on how to interrogate heretics, treating the whole thing as established fact.

The interrogations were conducted under torture, and torture produced exactly what torture always produces. The story the interrogator already had in mind, elaborated with whatever details were needed to make the pain stop. Under torture, lepers confessed. Then the confessions grew.

A rich Jew had funded the plot, the confessions said. Then the Jewish communities collectively. Then, as the story reached its final form, the Jews had been acting on instructions and money from the Muslim rulers of the East, from the Sultan of Babylon and the King of Granada, in a coordinated conspiracy to destroy Christendom from the inside by making Christians rot alive. Nothing about that has any correspondence with anything that could have happened.

France had no Muslim population to speak of. The leper houses were in no position to organize anything across a kingdom. And the men and women being accused were largely blind, mutilated, and dependent on charity. The accusation was accepted anyway at the highest level.

King Philip V authorized the arrests. What followed through June, July, and August of 1321 was one of the ugliest episodes in the whole history of the disease. Lepers were seized in their houses and dragged out of the hospitals that had been built to shelter them. Local lords in some regions did not wait for royal instructions at all.

They arrested and executed on their own authority, and then took the property of the condemned, because the property of the condemned was forfeit. The financial incentive is written into the documents. Burning a leper paid. They were burned.

In some places in ones and twos, at a crossroads or outside a town gate. In others in groups, in pits, with the whole population of a town watching. Chroniclers describe pyres of lepers, and the numbers given are unreliable in the way all medieval numbers are unreliable, but the geography is broad, from the southwest up into the center of the kingdom, wherever there was a leper house and a local authority willing to act. Consider what being burned meant for these particular bodies.

A man with advanced disease could not run. He could not see the fire coming. He could not feel the ropes cutting into wrists that had lost all sensation, so he would not have known how tightly he was bound. He could not shield his face.

And in the fire itself, the anesthesia gave way, because the nerve damage in leprosy is patchy. Plenty of skin still reported, so the burning was felt in some places and not in others. Some were not burned, but walled up. The royal edict of the 27th of August, 1321, ordered that lepers be confined permanently.

And at Limoges, those who were seized were branded and locked away under that order. And then, only about a month later, the Limoges group was released, despite the edict’s clear intention that the confinement be for life. Somebody in Limoges quite quickly stopped believing the story. Doubt surfaced almost immediately.

The confessions had been obtained under torture. The powders had never been produced in a form anyone could examine, and the wells kept giving water that did not make anybody leprous. Later chroniclers writing about 1321 grew visibly skeptical about the well-poisoning, and some of them said as much. But the machinery, once started, did not run backwards.

Jews were burned indiscriminately across Aquitaine and elsewhere during the same months, and the accusation of well-poisoning, having been rehearsed and accepted in 1321, was sitting ready and available in the collective memory of Europe when the Black Death arrived 27 years later. The pogroms of 1348 and 1349, which destroyed Jewish communities across the Rhineland and beyond, used the same accusation in almost the same words about the same wells. The leper plot of 1321 was a rehearsal, and nobody involved could have known that. The physician Amonant we mentioned earlier, seized at Huesca in 1322, that arrest makes sense in this light.

He arrived in Aragon a stranger in the immediate aftermath, and was accused of being both a leper and a poisoner, which by then were effectively a single charge. He was examined, found clear, released, and immediately left the kingdom. Knowing what had been happening across the border, you cannot blame him. Plague years, generally, were when lepers were most likely to be driven out of towns.

The pattern turns up repeatedly across the later 14th and 15th centuries. An epidemic arrives, the civic authorities look around for a source of pollution, and the men and women with the visible disease are pushed out beyond the gates, whether or not their own institution was inside them. Sometimes the sweeps caught up vagrants, prostitutes, and the unlicensed poor at the same time, because the categories blurred in practice. Anybody visibly diseased, visibly poor, and visibly outside the parish structure was subject to the same procedure.

The people being expelled were frequently blind, unable to walk without pain, and unable to carry anything. Expulsion in November from a walled town into open country, with no house to go to. Nobody wrote down what happened to them next. Back inside the walls, away from all that, the daily rhythm of these houses had a strangeness of its own.

A leper house was, formally and legally, a religious community. The inmates were brothers and sisters. They took an oath on admission. They were bound to obedience, and they owed the house a specific quantity of prayer.

That last point is the crucial one, and it explains the money. A wealthy man endowing a leper hospital was buying prayers, masses, and psalms said daily in perpetuity by people whose suffering made their prayers unusually valuable in the spiritual economy of the time. Somebody undergoing purgatory on Earth was thought to have a direct line. So the founder’s soul was the product, and the lepers were the workforce.

The day was built around the chapel. Statutes commonly required the inmates to recite a fixed number of Paternosters and Ave Marias at set hours, morning and evening, and often to attend mass daily. Illiterate inmates counted them on knotted cords. Blind inmates recited from memory.

In houses too small for a resident priest, a chaplain came in from the parish. The lepers of one Norfolk house were bound to pray for the founder’s family by name. The practical reality of fulfilling that obligation is grotesque. A man whose hands have curled shut cannot hold a rosary.

A man with no fingertips cannot count knots. A man whose eyes will not close and whose corneas have scarred over cannot see the altar he is facing. A woman with a perforated palate cannot pronounce the Latin cleanly. And all of them, morning and evening, saying the same words for the soul of a bishop who died 40 years earlier.

The buildings themselves varied from substantial stone complexes down to a couple of cottages and a chapel. The larger houses had a hall or dormitory arrangement, a chapel, a kitchen, a brewhouse, outbuildings, a garden, and their own cemetery, which the Third Lateran canon had specifically guaranteed them. Some had individual small chambers rather than a shared dormitory, which was an enormous kindness for people with suppurating wounds and incontinence. Many did not.

A shared dormitory in January went something like this. Straw mattresses changed rarely. Wool blankets. A dozen or 20 people in a room with a hearth or a brazier, and no ventilation to speak of, because ventilation in a medieval winter means dying of cold.

Chronic ulcers on feet and hands and legs discharging constantly. Bandages of linen strip washed and reused. Nasal discharge running continuously in patients who could not always feel their own faces. Incontinence in the advanced cases.

Vomiting. And in a large proportion of them, active pulmonary tuberculosis, which co-infects leprosy sufferers at extraordinary rates, meaning a room full of people coughing up infected sputum in each other’s direction all night. The statutes are not silent about the consequences, either. Rules about the disposal of soiled straw and the emptying of latrines appear in the surviving ordinances of several houses, alongside prohibitions on inmates keeping animals in the dormitory and on bringing food to bed.

Rules like that get written because somebody was doing it. Washing did happen, and the evidence for it is better than the popular picture allows. Sherburn’s inventory listed bathing vats. Several continental houses employed a servant specifically for washing the sick and their linen.

Some had a piped water supply. The leper hospital of St. Bartholomew at Oxford and others sat near springs deliberately. Whether any of that kept pace with a dozen chronically infected wounds is another matter entirely.

The care of the dying is where these institutions show their best face. Sherburn’s ordinance is explicit: fire, candles, and all necessaries until the sufferer recovered or died. Somebody sat up with them then. In a house with a chaplain, the last rites were administered properly.

Confession, anointing, viaticum. And this meant enormously to people who had been told at their diagnosis that they were dead to the world. Whatever the ceremony had said, the church came to their bedside at the end and treated them as a Christian dying in good standing. Then they were buried in the house’s own consecrated ground, in a proper grave oriented east, sometimes with a pillow of chalk or a stone under the head.

The archaeology confirms all of that. The graves in these cemeteries are not pits. At Winchester and at Chichester and at the Danish sites, the burials are laid out in rows, supine, extended, oriented correctly, in individual graves. Somebody dug each one and put each body in it with care.

The pilgrim at Winchester got a grave carved out of bedrock with a niche for his skull. A great deal of labor for a young man who had lost his feet to a disease that made him untouchable. The internal politics could be vicious, though, and the surviving records do not pretend otherwise. A master or prior ran the house, controlled the food, controlled the money, and in many cases controlled admission and expulsion.

Inmates elected representatives in some houses, held keys, and had a voice in the disposal of the endowment. In others, they had no voice at all. Disputes between inmates and masters reached the bishop’s court and the royal courts. Complaints about short rations, about the substitution of worse bread, about the diversion of the ale allowance, about the master’s relatives eating at the house’s table, appear repeatedly across two centuries in England and France alike.

And inmate against inmate. Statutes prescribe punishments for fighting, for theft from a fellow brother, for drunkenness, for slander, for refusing to take a turn at a duty. Punishments included loss of rations for a set number of days, exclusion from the chapel, corporal punishment, and at the far end, expulsion. Taking a man’s bread away for three days in a house where the bread was the whole of the diet was a serious act.

Expelling him was a death sentence with an unspecified date. So the picture of the interior is a religious community running on prayer and endowment income, in which people at every stage of a disfiguring disease lived at close quarters under strict discipline, in conditions that ranged from decent to appalling, depending on the wealth and honesty of whoever was in charge that decade, and in which the ordinary human capacity for pettiness, theft, and violence carried on operating exactly as it does everywhere else. Not everybody got a bed, though, and the ones who did not are the part of this story with almost no documentation at all. Do the sums on the accommodation.

Three hundred and twenty English houses, most of them small. Five beds, ten, occasionally the 65 at Sherburn. Even generously, that is a few thousand places in the entire country, and many of those places were occupied by paying corrodians or the founders’ relatives. The number of people in England with leprosy across those centuries was considerably larger.

So the majority of sufferers never lived in an institution. They stayed at home in their villages, or they went on the road. The roadside life left physical traces in the landscape. Leper huts stood at crossroads and outside town gates, timber and turf, a hearth, a door.

Some churches were cut with a narrow angled opening in the wall, a squint or hagioscope, positioned so that somebody standing outside in the churchyard could see the elevation of the host at the altar without entering the building. Look for them in English and French parish churches and you will find them low down, angled toward the high altar, often on the north side away from the porch. Whether every one of those openings was made for lepers is arguable, but the arrangement is exactly what the prohibitions required: attendance without entry. Leper stones survive, too, hollowed blocks set at a distance from a settlement where a villager could leave bread or a coin, sometimes with vinegar in the hollow to wash the money, and then withdraw before the leper came to collect it.

A transaction conducted with nobody present at either end. Winter on the road did specific things to these bodies. Feet with no sensation cannot detect frostbite. A man walking on ulcerated soles through frozen mud will not feel the tissue freeze and will not feel it thaw and will not know anything is wrong until the toes blacken.

Dogs went for the ulcers on sleeping beggars, and that is exactly the detail in the parable of Lazarus, the dogs licking his sores, and that detail was included because the audience had seen it happen. Robbery was constant, since a blind man with clawed hands cannot defend a purse, and nobody would touch a leper to help him up. Family arrangements varied in ways that surprised people. Canon law did not dissolve a marriage on grounds of leprosy.

The healthy spouse was expected to continue the marriage, and while there was argument about the conjugal debt, the bond stood. Some spouses moved into the leprosarium alongside the diseased partner and lived there as a servant of the house. Others did not, and the diseased partner went out the door. Children of leper parents were a standing problem.

Some houses admitted them. Some communities took them in. And some children were simply diagnosed alongside their parent and disappeared into the same institution. Those 43 individuals under 20 years old in the Odense cemetery are what that looks like in the ground.

Children who lived in a leper hospital and died in one before they were old enough to have had a life anywhere else. Literature is where all of this got processed, and the literary lepers show you plainly what audiences were afraid of. Robert Henryson wrote The Testament of Cresseid in Scotland in the later 15th century, as a sequel to Chaucer’s Troilus and Criseyde. In his version, Cresseid, having betrayed Troilus and then been discarded by Diomede, is put on trial by the planetary gods and sentenced.

Saturn strikes her. She wakes, goes to a mirror, and sees what has happened to her face. Henryson’s description of her disease is so clinically precise that in 1841, the physician Sir James Young Simpson, the man who introduced chloroform into obstetrics, was able to identify the specific form of leprosy from the poem alone. Henryson had seen this.

He knew what the voice sounded like, what the complexion looked like, how the eyes changed, what happened to the hair. Scotland still had leprosy when he was writing, when England had largely lost it. Cresseid ends the poem in a leper spital with a cup and a clapper among other lepers begging by the roadside. And the scene that gives the poem its power is the one where Troilus rides past her without recognizing her, feels an inexplicable stirring of memory at the sight of a beggar he does not know, and throws down a purse of gold before riding on.

He never learns who she was. She learns who he was. And the recognition kills her. Amis and Amiloun, a romance that circulated in several languages, takes the disease in a completely different direction.

Amiloun contracts leprosy as a consequence of a sworn oath and is reduced to beggary, driven out, carried about in a cart by a loyal servant boy. And the cure, when it comes, requires the blood of his sworn brother’s children. Amis kills his own two children and washes Amiloun in their blood, and Amiloun is healed, and the children are then miraculously restored. That is the moral logic on offer.

Leprosy is so absolute a condition that only child sacrifice can undo it, and a poem can consider that a happy ending. Guy of Warwick has its hero, at the end of a career of adventure, retire into penitential poverty and beg at his own gate, unrecognized by his wife. The Cursor Mundi and other devotional compilations return steadily to lepers as objects of charity and as tests of the soul planted in the path of the wealthy to see what they will do. Across all of it, the leper occupies the same double position we found in the theology.

Fate, punishment, test, sacred wound, and warning all at once. And in Beroul’s Tristan, a punishment specifically designed to be worse than being burned alive. The disappearance, then. Leprosy did fade out of most of Europe, and how that happened is not settled.

The timing is reasonably clear, even if the cause is not. The disease was at its height in Western Europe from roughly the 11th century into the middle of the 13th. New foundations of leper houses drop off sharply after that. By the middle of the 14th century, the English houses are already struggling to fill their beds with actual lepers, and that is precisely when the corody problem takes hold and paying pensioners start moving in.

By the 16th century, the disease has effectively gone from England outside a few pockets in the far southwest, while it lingers on in Scotland, Scandinavia, Iceland, and parts of the Baltic for centuries longer. Several explanations have been put forward, and the honest position is that they may all be contributing at once. The first is tuberculosis. M.

leprae and the tuberculosis bacillus are closely related and share a great deal of antigenic material, so exposure to one confers partial immunity against the other. Tuberculosis spread explosively through Europe’s growing, crowding towns from the 13th century onward. It also kills far faster than leprosy. A person with active pulmonary tuberculosis in the 14th century was often dead within a couple of years.

So the proposal is that tuberculosis both immunized the population against leprosy and killed off the people whose immune systems were least capable of handling either organism, before leprosy had the 15 or 20 years it needed to declare itself. Tuberculosis got there first and took the same victims. The second is the plague. The Black Death arrived in Europe in 1347 and killed somewhere between a third and a half of the population in three years.

People who were malnourished, immunologically compromised, and living 20 to a room in institutions were not well placed to survive it. Whole leprosaria would have emptied in a fortnight, and a disease with a 20-year incubation period cannot recover from that kind of interruption in its chain of transmission quickly. The third is the segregation itself, and this is where the story turns cold. The 2013 genome work established that the bacterium had not changed in a thousand years, no loss of virulence, essentially the same organism.

So whatever changed changed on the human side. Susceptibility to leprosy has a substantial genetic component, and it runs in families. Put the institutions back into that frame. Two and a half centuries of taking the people most susceptible to this disease, identifying them by public examination, moving them into separate buildings, forbidding them to marry, enforcing celibacy on pain of expulsion, and burying them in separate ground.

Whether or not anybody involved understood it in those terms, the leper houses of Europe functioned as reproductive dead ends for a particular set of inherited vulnerabilities. Three hundred and twenty houses in England, perhaps 2,000 in France, running for 250 years. Europe may have bred the susceptibility out of itself, one leper house at a time. The 2018 work complicated things further by showing how much strain diversity was already present in medieval Europe, including lineages now found on other continents.

So the traffic ran both ways, and the crusader ships, and the pilgrim roads, and the trading fleets that were carrying the disease around the Mediterranean were also carrying it outward into places where it settled and stayed. That young man at Winchester with his scallop shell and the Central Asian strain in his bones is a single visible node in a network that covered half the world. What happened to the buildings tells its own story. As the lepers stopped arriving, the endowments remained, and the endowments needed spending.

Some houses became almshouses for the ordinary sick poor. Chichester did exactly that. It carried on straight through the Reformation under a new description. Others became pesthouses and plague houses, taking in quarantine cases during epidemics, and the word for a leper house followed them.

Lazar house became lazaretto, and lazaretto became the standard European term for a quarantine station on an island or a headland, where ships’ crews were held for 40 days. Some became poorhouses. Some became madhouses. Bethlem in London, which gave the English language the word bedlam, began as a religious hospital of exactly this general type before it became what it became.

The buildings outlasted the disease and kept doing the same job under new names, holding the people a town did not want inside its walls. In the north, though, leprosy did not go anywhere. Henryson was writing about lepers in Scotland in the 15th century because Scotland still had them. Norway had substantial numbers into the 19th century, concentrated along the western coast, and built new leprosaria to hold them.

The whole story turns into modern medicine in a hospital in Bergen in 1873, when a Norwegian physician named Gerhard Armauer Hansen looked at material from a leprosy nodule under a microscope and saw rod-shaped bodies in it. He had found the organism. It was the first time in history that a bacterium had been identified as the cause of a chronic human disease, and he found it in a disease everyone had spent 800 years explaining in terms of sin, semen, bad air, corrupted blood, and conception on holy days. Every one of those explanations collapsed in front of a microscope slide in Bergen.

Hansen’s discovery did not end the segregation. Norway passed laws compelling the isolation of lepers in 1877 and 1885. Across the world, the 20th century built more leper colonies than the Middle Ages ever did, on islands, on peninsulas, in deserts. Kalaupapa on the island of Molokai in Hawaii received forced arrivals from 1866 onward, and the last of its residents were still living there in the 21st century.

Japan’s leprosy prevention law, which allowed compulsory confinement, was not repealed until 1996, and the survivors of the Japanese sanatoria won a court judgment against their own government afterwards. India has hundreds of settlements founded as leprosy colonies, many of them still inhabited by the descendants of the original residents. Effective treatment arrived in stages. Sulfone drugs from the 1940s, then the resistance problem, then multi-drug therapy from the early 1980s, which the World Health Organization has supplied free of charge worldwide since 1995.

Multi-drug therapy cures the infection reliably. It cannot regrow a nerve. Somebody diagnosed late, with the hands and feet already gone and the eyes already scarred, is cured and permanently disabled at the same time. Early detection is the whole game, and it has not gone away.

Leprosy still occurs in more than 120 countries. Roughly 200,000 new cases are reported every year, and the reported figure for 2024 was 172,717, including 9,397 children. Children are the number that epidemiologists watch, because a child with leprosy means recent active transmission in a household right now. Brazil, India, and Indonesia each report more than 10,000 new cases a year.

The reservoirs are the last strange piece of it. Nine-banded armadillos across the southern United States and parts of South America carry M. leprae, and human cases have been traced to contact with them. And in the British Isles, red squirrels carry it, too.

Squirrels on Brownsea Island and in parts of Scotland have been found with leprosy, showing the nodular changes on their muzzles and ears. And the strain in some of them is closely related to the one recovered from medieval human skeletons in England. So the organism that emptied the young man’s feet on that Winchester hillside, and put the graveyard soil on the shoes of a thousand frightened people in a thousand parish churches, and put people onto pyres across half of France in the summer of 1321, is still out there in the English woods, in the squirrels, waiting on the off chance that something changes.