The midwives had barely finished when the queen recoiled. The child delivered on November 6th, 1661, in a dimly lit chamber of the Royal Palace of Madrid, had a head grotesquely large, labored breathing, and a body that seemed wrong in ways the most experienced attendants could not immediately name. Queen Mariana reportedly shuddered at the sight of her own son and refused to nurse him. This was not maternal cruelty but something closer to instinct, a primal horror at an infant who should not have existed in that form.

Mariana understood the boy’s condition better than she could ever admit. She was not merely Charles’s mother. She was also his cousin and his aunt, because her husband Philip IV, the King of Spain, had married his own niece. From the hour of his birth, the heir to the greatest empire on earth was already anatomically doomed.

To understand how a baby could be born so damaged that his mother flinched from him, the story has to begin generations earlier. The Habsburgs had a saying: “Let others wage war. You, happy Austria, marry. ” It sounded like a strategy for building alliances through matrimony.

In practice, it meant something far more dangerous. For nearly two hundred years, the Spanish branch of the Habsburgs married cousins, uncles married nieces, and double first cousins united in matrimony. They called it maintaining the purity of the blood. Scientists now call it genetic suicide.

The numbers are damning. Over eighty percent of Spanish Habsburg marriages were between close relatives, not distant cousins one might meet once at a family gathering but people who shared grandparents or sometimes parents. By the time Charles was born, all eight of his great-grandparents descended from a single couple: Philip I and Joanna of Castile. When modern geneticists calculated Charles’s inbreeding coefficient, the percentage of his genes that were identical copies from common ancestors, they arrived at 0.

254. That is a number worth pausing on. A child of brother-sister incest has a coefficient of 0. 25.

Charles II of Spain was therefore more inbred than someone born to siblings. But numbers cannot convey what this meant in the helpless body of a living child. Baby Charles could not suckle properly. His mouth was already misshapen, his skull bones had not fused correctly, and his head was swollen and lopsided.

Court physicians noted his weak suck and his desperate struggle to feed. In an era before infant formula, that struggle was life-threatening. The wet nurses hired to feed him reported something stranger and more troubling: the infant rarely cried. Not because he was content, but because he seemed to lack the energy.

He lay pale and still, his oversized head lolling to one side, his breathing shallow and raspy. The best physicians in Spain had never seen an infant so fundamentally broken. As months turned to years, the full catastrophe revealed itself. At age four, Charles still could not walk.

His legs were thin as sticks, bowed by rickets, unable to support even his small body weight. Servants carried him everywhere in specially designed chairs. The future king had to be transported like a baby. At age four, he also could not speak a single word.

His tongue was already growing abnormally and filled his mouth. That infamous Habsburg jaw was already protruding. When he finally produced his first words sometime after his fourth birthday, they were slurred, wet, incomprehensible. The court chroniclers noted with delicacy that his majesty’s speech required interpretation.

What they meant was this: his tongue was so enlarged that it constantly protruded from his mouth, his lower jaw jutted so far forward that his lips could not close, and when he attempted to speak, saliva poured from his mouth. Royal attendants stood ready with silk cloths to constantly wipe the drool from the chin of the boy who would be king. The Habsburg jaw is easy to picture if one imagines a normal human skull and then pulls the lower jaw forward several inches. The upper jaw never grew to match.

The result is a mouth that can never fully close, teeth that can never meet, and a tongue with nowhere to rest. In portraits, artists tried to minimize it, painting Charles with his mouth slightly open as if caught mid-word. In reality, his mouth was always open, because it could not physically close. Foreign ambassadors meeting the young prince struggled to maintain their composure.

One French diplomat’s private letters described the shock in blunt terms. The prince’s appearance defied description. His jaw protruded so far that he seemed to have two faces, one stacked in front of the other. When he attempted to eat, food fell from his mouth.

When he spoke, one had to stand back to avoid the spray. Eating was its own humiliation. Charles could not chew. His upper and lower teeth were separated by such a gap that they never met.

Every meal of his entire life was swallowed whole. Court dining became an exercise in creative cuisine. Meats were cut into tiny pieces, vegetables pureed, bread soaked in wine until it dissolved. The English ambassador, Alexander Stanhope, left one of the most deeply unsettling descriptions of the king at table.

His Catholic majesty swallows all he eats whole, Stanhope wrote, for his nether jaw stands so much out that his two rows of teeth cannot meet. To compensate, he has a prodigious stomach and swallows a whole lamb at two meals. Physical deformity was only the beginning. Charles suffered from constant illness.

Measles nearly killed him at age six. Chickenpox followed, leaving him covered in scars. Then came rubella, then smallpox. Every disease that swept through the palace found a willing host in Charles; his compromised immune system offered little resistance.

Smallpox struck when he was nine, and for weeks he lay between life and death. His face became a battlefield of pustules and lesions, and when he finally recovered, the scars joined the catalog of his disfigurements. The disease also left a hidden complication. Physicians noticed fluid building in his skull.

His already large head began to swell further. Today it is called hydrocephalus, water on the brain. In the seventeenth century, it was called another curse upon the prince. The pressure caused blinding headaches, vision problems, and possibly the seizures that would plague his later years.

At age ten, Charles’s education was a palace scandal. Not because he was rebellious or lazy, but because he could not learn. Tutors reported that lessons had to be repeated dozens of times. Basic mathematics was beyond him.

Latin might as well have been ancient Egyptian. His handwriting, on the rare occasions he attempted it, was that of a child years younger. One tutor’s private notes, discovered centuries later, painted a heartbreaking picture. His majesty tries with great effort, but retains nothing, the tutor wrote.

I explain a concept, and by the next day, it is as if he has never heard it. His attention wanders. Sometimes he stares at nothing for long periods. When asked what he is thinking, he cannot say.

As Charles entered what should have been puberty, his body betrayed him in new ways. He grew, but barely. His voice stayed high and thin. He developed almost no body hair.

The characteristics that marked a boy becoming a man never appeared. The court physicians held hushed conferences and discussed what they observed but dared not put into official records. The prince showed no interest in women. No interest in men either.

He existed in a strange childlike state, neither boy nor man, something in between. This terrified the court, because Charles had one job above all others: to produce an heir. The entire Spanish Empire, stretching from Europe to the Americas to the Philippines, needed the bloodline to continue. But how could a man who could not grow a proper beard father children?

At age eighteen, they decided to find out. Charles married Marie Louise of Orléans, a seventeen-year-old French princess who was by all accounts beautiful, intelligent, and healthy. The contrast between bride and groom shocked the wedding guests. She was radiant.

He was ghastly. She walked gracefully down the aisle; he shuffled, supported by attendants. When it came time for the kiss, observers noted that Marie Louise visibly steeled herself before leaning in. The wedding night was not merely disappointing; it was a catastrophe that determined the fate of empires.

Charles was completely incapable of consummating the marriage. Not unwilling. Incapable. His body simply did not function as a man should.

Marie Louise, raised in the sophisticated French court, tried everything. She was patient, kind, and according to palace gossip, attempted to instruct her husband in the basics of marital relations. Nothing worked. Years passed.

No pregnancy. The queen underwent humiliating examinations to determine whether she was the problem. The physicians declared her perfectly fertile. Everyone knew the real problem, but no one would say it officially.

The pressure crushed them both. They were subjected to increasingly desperate fertility treatments. She was forced to drink vile concoctions of herbs and animal organs. He consumed potions containing ground pearls and bull’s blood.

At one point, a specialist prescribed eating the dried penis of a stag. Nothing worked, because nothing could work. Charles’s reproductive system was as malformed as the rest of him. Charles’s mother, desperate for a grandchild, consulted mystics and holy men.

One suggested Charles was cursed and that sleeping next to holy relics might break the spell. That failed. Then she escalated to something that still shocks historians: she arranged for her son to spend nights lying beside exhumed bodies of saints and former kings, including his own father. The theory was that the holy essence of the dead would cure his impotence.

Picture the king of Spain, drooling and malformed, lying next to decomposing corpses in a desperate attempt to gain the ability to father a child. Ten years of marriage passed. Ten years of failed attempts. Ten years of humiliation.

Then Marie Louise died suddenly at age twenty-six. The official cause was listed as appendicitis, but rumors swirled. Had she been poisoned? Had the strain driven her to suicide?

No one would ever know. What is known is that Charles was genuinely devastated. Despite everything, he had grown to love his wife, perhaps the only person who had shown him real kindness. Within months, the council pressed him to remarry.

They selected Maria Anna of Neuburg, a German princess from a famously fertile family. Her parents had produced seventeen children. Surely, the advisers reasoned, such robust genes could overcome even Charles’s deficiencies. They were wrong.

Maria Anna never became pregnant. Not once. By then, Charles’s health had deteriorated further. Courtiers whispered that he looked like an old man, though he was barely thirty.

His hair fell out in patches. His teeth, the few visible behind that protruding jaw, rotted and fell out. He shuffled when he walked, when he could walk at all. The seizures began in his thirties.

Without warning, Charles would collapse, his body convulsing, foam mixing with the ever-present drool. When he recovered, he often did not recognize the people around him. He began talking about seeing ghosts, hearing voices, feeling invisible hands touching him. The court was terrified.

Was their king going mad on top of everything else? His nickname, El Hechizado, the Bewitched, took on new meaning. People genuinely believed Charles was under a curse. The Spanish Inquisition became involved.

Exorcists were brought in. At one point, the king’s own confessor was arrested on charges of using witchcraft to worsen the royal condition. The trial caused a sensation, though no amount of exorcism could repair genetic damage. Charles himself believed he was cursed.

In lucid moments, he wept and asked what he had done to deserve such punishment. He wore amulets, carried holy relics, and submitted to increasingly bizarre purification rituals. Nothing helped. Nothing could help.

His genetic code was the curse, written into every cell of his body. By age thirty-five, Charles looked ancient. Contemporary descriptions are hard to read. His skin hung loose on a skeletal frame.

His jaw seemed to grow more pronounced as the rest of his face wasted away. He was completely bald, his scalp covered in sores. He could barely walk, shuffling a few steps before needing rest. His speech, always difficult, became nearly impossible to understand.

In his final years, his mind deteriorated rapidly. He sat for hours staring at nothing, drool pooling on his clothes. When spoken to, he often did not respond. When he did speak, he rambled about demons and angels, about his dead wife, about children he would never have.

The king of one of the greatest empires on earth had become a hollow shell. The end came in 1700. Charles was thirty-eight years old, not elderly by any standard, but his body was shutting down. He could not eat even his specially prepared mush.

He could not stand without help. He spent his days propped in bed, gasping for breath, his hydrocephalic head causing unbearable pressure. On November 1st, after days of agony, Charles II died. The autopsy stunned even the physicians who had treated him for years.

The embalmers cut open the body and recoiled. Their report, written in clinical Latin but dripping with barely concealed horror, described a body that should not have sustained life for as long as it had. His body contained not a single drop of blood. This was not poetic exaggeration.

Charles’s circulatory system had essentially shut down; his blood had clotted or simply vanished. His heart was described as the size of a peppercorn. Not literally that small, but shriveled, blackened, barely recognizable as the organ meant to pump life. His lungs were corroded, scarred from repeated infections, their tissue resembling pumice stone more than organs meant for breathing.

His intestines were described as rotten and gangrenous. Parts of his digestive system had literally died while he was still alive, explaining the horrific pain of his final years. Then came the most telling detail, the one that confirmed what everyone suspected but no one had dared say officially. Charles had only one testicle, and it was black as coal.

This single atrophied, dead piece of tissue was all that remained of a functioning reproductive system. No wonder he could not father children. It was a miracle he had survived puberty at all. And his brain had indeed been full of water.

The hydrocephalus had left barely any room for actual brain tissue. How Charles had managed to speak, think, and rule at all, however poorly, remained a medical mystery. Modern genetic analysis has supplied the why behind the horror. That inbreeding coefficient of 0.

254 meant a quarter of Charles’s genome consisted of identical copies of genes. In those repeated sequences lurked the instructions for his destruction. Scientists now believe Charles suffered from at least two major genetic disorders. The first was combined pituitary hormone deficiency.

His body could not produce the hormones needed for normal growth and development, explaining his short stature, his failure to sexually mature, his muscle weakness, and his cognitive problems. His pituitary gland, the master controller of the endocrine system, was essentially non-functional. The second likely condition was distal renal tubular acidosis. His kidneys could not properly regulate his blood chemistry, causing the rickets that bent his legs, the muscle weakness that left him unable to walk, and possibly contributing to the hydrocephalus that swelled his skull.

Either condition alone would have been challenging. Together, they created a cascade of failures throughout his body. Add the Habsburg jaw, the genetic condition known as mandibular prognathism, and the result was a perfect storm of genetic disasters. Some researchers have proposed an even rarer possibility: a lysosomal storage disease called aspartylglucosaminuria.

Patients with this condition develop normally for their first few years, then show delays. By adulthood, they have coarse facial features, intellectual disability, and shortened lifespans. The match with Charles’s symptoms is eerily exact. And Charles was not uniquely unlucky.

He was the inevitable result of systematic inbreeding. Of the thirty-four children born to Spanish Habsburg monarchs, more than half died before age ten. The dynasty was literally breeding itself to death. Charles was simply the final, most extreme example.

When he died without an heir, it triggered the War of the Spanish Succession, a conflict that reshaped Europe. The Spanish Empire built over centuries shattered because one man’s body was too broken to produce a single child. The Habsburg line that had ruled Spain for nearly two hundred years ended not with an assassination or a revolution, but with a king so inbred that his own flesh betrayed him. The Bourbon dynasty that replaced the Habsburgs learned the lesson.

Royal marriages remained political, but the extreme inbreeding that created Charles II was never repeated. The nightmare of the Habsburg jaw, the horror of the autopsy, the tragedy of a king who could not chew his own food, these became cautionary tales whispered in royal courts across Europe. Charles II remains in medical textbooks as the ultimate example of genetic collapse. Students studying genetics no longer see only a royal portrait; they see an inbreeding coefficient.

His Habsburg jaw has become shorthand for the dangers of a closed gene pool. In a strange way, his suffering contributed to our understanding of heredity and the importance of genetic diversity. But beyond the medical curiosity, beyond the political consequences, there was a human being. Charles II lived every day in a failing body.

He endured constant pain, constant humiliation, and the knowledge that he was failing his most basic duty as king. He was mocked as the Bewitched when his only curse was his ancestry. In his final letter, dictated because he could no longer hold a pen, Charles wrote of hoping to find in death the peace that had eluded him in life. For a man who had endured four decades of physical and mental anguish, who had been propped on the throne like a grotesque puppet, death must have felt like mercy.

Visitors to the Museo del Prado in Madrid pause before his portrait, struck by the deformities even the court painter could not fully hide. The jaw that could not close, the tongue that could not fit, the body that could not function, the genome that had turned against itself. Charles II of Spain was never cursed by witches or demons. He was cursed by his own family tree, a tree so tangled it had become a noose.

In trying to keep power in the family, the Habsburgs destroyed their own bloodline. Biology always has the final say, and sometimes that final say is horrifying beyond imagination.