In the summer of 1680, prisoners in the dungeons of Vincennes began speaking a name that would shake the throne of France. The name belonged to Françoise de Rochechouart, Marquise de Montespan, the most powerful woman in the kingdom, the woman people called the true queen of France. According to the testimony gathered by the police, she had bought love powders ground from dead men’s bones, arranged masses sung over naked women while infants had their throats opened above a chalice, and plotted the poisoning of the king himself. What Louis XIV did with those statements, and what he did to the people who made them, became one of the darkest stories of the age of Versailles.

Some of those people were burned alive in public squares. Others were chained to the walls of remote fortresses for the rest of their lives under written orders that they be flogged if they ever tried to repeat what they knew. The woman at the center of it all was baptized Françoise de Rochechouart on October 5, 1640, at the château of Lussac in Poitou. Her father was the Duke of Mortemart, her mother a lady-in-waiting to the queen mother.

The family was ancient, and they were famous for something stranger than land and titles. Contemporaries called it the esprit Mortemart, a particular way of turning a phrase, a slow drawling delivery that made ordinary sentences funnier than they had any right to be. All four Mortemart siblings had it. Françoise would grow up to be the finest shot in the family.

At twelve she was sent to the convent of Sainte-Marie at Saintes. She was genuinely devout, taking communion weekly, well beyond what was expected. Somewhere along the way she stopped answering to Françoise and started calling herself Athénaïs, after the Greek goddess of wisdom and war. At twenty she came to court, first as maid of honor to the king’s sister-in-law, then in the household of the queen herself.

She built a reputation as one of the most amusing unmarried women in France while keeping her conduct spotless. In 1663 she married Louis Henri de Pardaillan de Gondrin, Marquis de Montespan, a hot-blooded Gascon nobleman. The marriage produced two children, but money was a problem. The couple had the highest possible birth and no funds to match.

Court life put an obvious solution in front of her every day. The money in France lived in a twenty-something king who was busy building the most expensive stage set in human history and who had a habit of falling in love with his wife’s ladies. The position that mattered belonged to Louise de La Vallière, the official mistress. Louise was shy, sincerely pious, genuinely in love with the king, and consumed by guilt about it.

Around 1666, Athénaïs began a campaign with the clean lines of a military operation. She made herself the close friend of the queen and of Louise de La Vallière. Both trusted her. And when the king needed entertaining company at private suppers, the woman both recommended was their dear, witty, trustworthy friend.

They carried the fox into the hen house themselves. By the spring of 1667 the affair was done. The king made Louise a duchess, a shower of honors that fooled no one. At court, a big public gift to a mistress was the standard way of announcing that her services were concluded.

But the affair between two married people, double adultery, was a far graver scandal in the eyes of the church. The affair needed cover. The cover they chose was Louise. She was kept on as the official mistress, the public decoy, made to share connecting apartments so the king could pass through her chambers on his way to Athénaïs.

She endured that arrangement for roughly seven years. Meanwhile the husband had found out. The Marquis de Montespon’s reaction to being cuckolded by the king was one of a kind. The normal reaction was gratitude.

The Marquis instead went magnificently berserk. He made scenes, screamed at his wife in front of witnesses, compared Louis to King David stealing the wife of Uriah. The king had him arrested and then exiled to his estates in Gascony. Distance did the opposite.

The Marquis announced that his wife had died, put his household into mourning, and held a formal funeral complete with a requiem mass, making his two small children stand there and mourn a mother who was alive. Then he drove around in a carriage draped in black with an enormous pair of stag’s horns bolted to the roof, so everyone understood exactly what had been done to him. Year after year he had a requiem sung for his living wife. The threat that shaped everything was the law.

Any child Athénaïs bore was presumed by law to be her husband’s, and he was exactly the man to claim the king’s children as his own property. The first child of Athénaïs and Louis arrived in the spring of 1669. The birth had to be a covert operation. The babies were handed off within days of delivery to a hired household in a discreet house on the Rue des Tournelles.

The woman running that household was Françoise d’Aubigné, the widow Scarron, poor, respectable, clever, and known in the Paris salons. She took on the secret royal nursery as a job and then fell completely in love with the children. In twenty years she would effectively be queen of France, and Athénaïs would have handed her the ladder rung by rung. Children kept arriving through the 1670s, seven in all.

In December 1673 the king legitimized them, gave them the surname de Bourbon, and had the letters registered by the Parliament of Paris. The mother was never named. Naming Athénaïs meant handing the Marquis de Montespan a legal opening, so the lawyers simply omitted her. In 1674 the crown finished the job of neutralizing the husband.

Six judges granted a formal separation of person and property. The years from the mid-1670s were the summit. She was the most entertaining person in the palace. The king made her laugh daily for over a decade.

Her conversation became a court attraction in its own right, and foreign ambassadors were steered toward her apartments. The Mortemart family collected on her position like shareholders at a dividend. Her father picked up the governorship of Paris. Her brother got a marshal’s baton.

At Versailles she eventually held a suite of some twenty rooms on the first floor close to the king. The queen made do with half that, one floor up. The king built her Clagny, which consumed something like two million livres, with gardens by Le Nôtre. Her losses at the gaming table ran to figures that look like printing errors.

One Christmas she was said to have lost 700,000 écus in a single sitting and then staked 150,000 pistoles on three cards and won it back. Living at that altitude did not soften her. She ridiculed ministers, generals, duchesses, whoever wandered into range, purely to keep her audience of one amused. This made her feared and hated in a way that matters enormously for what came later.

Underneath it all, two clocks were ticking. The first was biological. She was closing on forty, and the king’s eye had begun to travel. The second clock was ticking in rented rooms behind the Rue Saint-Denis, where a network of women were selling other women the means to hold a man, or failing that, to bury him.

The way down runs through the most notorious murderess in France, Marie-Madeleine de Brinvilliers. She was tiny, delicate, pretty, born into serious money. She married a marquis, ran through his money and hers, and took a lover with a sideline interest in chemistry. Before she used poison on her family, she tested it.

Her method was charity. The Hôtel-Dieu, the vast public hospital, encouraged pious ladies to visit the sick poor, and the Marquise de Brinvilliers became a devoted visitor. She brought the patients little gifts, biscuits, jams, wine. Some of those gifts were dosed.

Then she came back to sit at the bedsides of the people she had poisoned, listening to their symptoms, noting how long each preparation took. Her father took eight months to die. She nursed him through it herself, administering what a later reckoning put at around thirty separate doses. He died believing his loving daughter had been the one comfort of his final year.

Her two brothers died in 1670 of the same slow corrosion. The unraveling came by accident. Her lover died in debt, officials inventoried his effects, and among them found a small red leather casket containing packets and vials of prepared poisons and a stack of her letters tying her to all of it. She ran, stayed ahead of them for more than three years, and was finally caught by a police officer who arrived at her convent dressed as an abbé and talked her into a romantic stroll beyond the convent walls.

Paris in the summer of 1676 treated her trial as the event of the decade. She was sentenced to be beheaded, her body burned, her ashes scattered. Before the execution came the question, torture to extract the names of accomplices. They gave her the extraordinary question, sixteen pints of water poured down her throat through a funnel.

She named no accomplices. That evening she was carted through enormous crowds in a tumbril. Madame de Sévigné, who was in the crowd, admitted in a letter that she saw nothing of the famous marquise but a bonnet. At the Grève her head came off with one clean stroke.

Madame de Sévigné wrote her daughter a line that has outlived almost everything else from that summer. “Well, it is done. Brinvilliers is in the air. ” She meant it as a joke.

Give it three years, and it stops sounding like one. The Brinvilliers case frightened the government in a specific way. She was an insider, well-born, wealthy, and she had operated undetected for the better part of a decade. If her, who else?

The king already had the right man in position to act. Gabriel Nicolas de La Reynie held the newly created office of Lieutenant General of Police of Paris. Now the king pointed him at the darkness the lanterns could not reach. The thread that started everything was a fortune teller.

In 1677 the police arrested a woman named Magdelaine de La Grange on fraud and poisoning charges. From her cell she reached out to the war minister Louvois claiming she knew matters touching the highest people in the kingdom. Then at the end of 1678 came the stroke of luck this whole affair pivots on. At a dinner party, a fortune teller and poisoner named Marie Bosse stood up and boasted about her marvelous clientele of duchesses and countesses, and declared that three more poisonings and she could retire rich.

One guest went home and quietly repeated it to the police. La Reynie sent in an officer’s wife posing as a desperate woman, and Marie Bosse sold her a preparation for the man’s soup. Early in January 1679 the police kicked in her door before dawn. Then the women began to talk and to name names.

Within weeks La Reynie understood the true scale of what he had opened. Paris in the 1670s supported a whole underground economy of fortune tellers, sorceresses, and abortionists. Their storefront trade was palmistry. The backroom trade ran deeper.

Love powders for wives losing their husbands. And for the customer whose problem could only be solved by a funeral, the flagship product, a fine white preparation of arsenic that Parisians had nicknamed poudre de succession, inheritance powder. The king’s response in April 1679 was to create a special royal tribunal to try it all in secret with no appeal. Paris immediately revived an older name for that sort of court.

The Chambre Ardente, the burning chamber. Over its lifetime it would hold 210 sessions and issue 319 arrest warrants. Every confession produced in that building was produced by people who had either just been through torture or were sitting in a room with the instruments, knowing they were next. In May 1679 Marie Bosse was burned alive.

And every interrogation transcript kept circling one address, one name. Catherine Monvoisin, La Voisin, the woman at the center of the web. She had been born around 1640, the same year as Athénaïs. By the 1670s she was rich, operating from a house with a large walled garden at Villeneuve-sur-Gravoire.

Her client list ran the entire vertical of French society, from servant girls up into the peerage. And per a stack of testimony, the reigning favorite herself, Madame de Montespan. The police took La Voisin on the 12th of March 1679, outside her parish church immediately after she had attended mass. Her interrogation was handled with a delicacy that had nothing to do with mercy.

A permit to put her to the question was drawn up and never used. A woman with her clientele under the wedges might scream out names the crown could not afford to have screamed. So the interrogations were conducted with wine on the table, session after session. She admitted plenty.

She fenced, though, around the highest names. On the 22nd of February 1680 she was carted to the Grève. At the stake she refused to play the ritual, shoved the burning straw away from herself five or six times, cursing through it, fighting the fire itself until the smoke took the fight out of her. The ashes went into the wind.

Her death solved nothing. By then the investigation had already burst its banks and was flooding upward into the nobility. In January 1680, warrants were being prepared against a clutch of aristocrats. The king sent a private warning to Olympe Mancini, the woman he had loved at nineteen.

She chose flight, leaving behind her fortune and her children. She also left behind a teenage son the French war office had recently rejected, a small unimpressive boy named Eugène. He walked away from France, offered his sword to the Austrian Habsburgs, and became Prince Eugene of Savoy, one of the greatest generals of the age, who then spent the following forty years methodically beating French armies across Europe. Then in the summer of 1680, the interrogators went back to the prisoners after La Voisin’s execution, and her daughter began to talk.

Marguerite Monvoisin said Madame de Montespan had been her mother’s client since 1667. The contact ran through intermediaries, principally a woman named Claude de Vin des Œillets, Athénaïs’s chambermaid, a figure the investigators found threaded through the whole file. The powders themselves flowed toward the palace for years, and from there, the testimony says, into the food and drink of the king of France, continuously across a decade. Then came Guibourg.

Étienne Guibourg was around seventy when the police took him, a squat old priest with a bloodshot wandering eye. Under interrogation he described the black mass as he himself had performed it. The woman for whom the mass was said served as the altar. She stripped naked and lay on her back, a napkin spread across her lower belly, and on the napkin over her navel stood the chalice.

The mass was addressed past God to other parties, the demons Modius and Astaroth. At the consecration, an infant was brought to the altar, held over the chalice on the woman’s body, and its throat was opened with a knife. The blood ran down into the cup. Where the infants came from, Guibourg answered without much difficulty.

Some were bought from a beggar for an écu, one silver coin. The mass took about an hour. The client dressed, paid, and went home. Then came the plot La Reynie considered the gravest thing in his whole mountain of paper.

According to Marguerite’s testimony, the requests coming out of the marquise’s circle had escalated to the removal of Louis XIV himself. A petition was prepared whose paper had been soaked in poison meant to work through touch. On the 5th of March 1679, La Voisin traveled to Saint-Germain and stood in the crowd of petitioners waiting to place the poisoned paper into the king’s hands. Petitioners that day were too many.

The session was cut short. The king took no papers. Seven days later the police took La Voisin with no idea what they had walked past. The one person who never got to address any of it in any forum was Athénaïs.

The king made sure no forum ever existed in which she could be charged or questioned. What he built instead of a trial is its own kind of horror story. The public machinery stopped first. The chamber was dissolved for good in 1682.

The final ledger of the affair reads 442 people accused, 367 arrest orders, 36 executions. Then a separate category. Dozens of prisoners could never be tried in any venue ever. They had heard the testimony about Madame de Montespan or given it.

A trial meant speech, and speech meant her name in the air. So they were removed from the justice system entirely by lettre de cachet, the king’s sealed order requiring no charge and permitting no appeal, and distributed for life among remote fortresses chosen for distance and deafness. The orders specify that they were to be flogged if they attempted to speak of the matters they knew. Some of those people were still alive in their chains past 1720, outliving the king, the marquise, and nearly everyone else in this story, imprisoned for the crime of having ears.

And at Versailles, nothing happened. Madame de Montespan remained at court at the king’s table, visited by the king daily. He never dined alone with her afterward. The daily visits continued and grew shorter, and the intimacy was over permanently.

The one thing the record makes plain is that he protected the mother of his children with the full machinery of the state, and while doing it he backed quietly and permanently out of her reach. The space he backed into was already occupied. The widow Scarron, governness of the secret nursery, had been rising for a decade on exactly the qualities Athénaïs lacked. Calm, discretion, patience, and a total absence of scandal.

In July 1683 Queen Maria Theresa died suddenly. Within months in secret, at night in the chapel at Versailles, Louis XIV married the widow Scarron. She was now unofficially but absolutely the queen of France and would hold that position for the remaining thirty-two years of the reign. Athénaïs stayed on at court for eight more years, and the eight years were a long public diminishment.

Her favorite son, the Duke du Maine, the boy with the damaged leg, loved the governness and grew openly cold to his mother. The final push came in 1691, and her own son delivered it. The king wanted her gone and wanted not to say so, and du Maine handled it, arranging matters so that his mother’s grand apartment was reassigned to himself. By one famous account, her furniture was simply put out.

Athénaïs asked the king whether he wished her to retire, received the answer in the form of a pension of half a million francs and no request to stay, and left Versailles in tears and fury. She never forgave du Maine. She was fifty years old and she had sixteen years left, and she spent them trying to buy back her soul. She placed herself under a spiritual director and asked him for the full program.

His conditions included formal submission to her husband. She was to write to the marquis, acknowledge her fault, and offer to return to him. She wrote the letter. The marquis’ answer was that he wanted neither to see her nor to hear of her ever in any form.

He had spent twenty years mourning a living wife, and when the living wife finally knocked, he declined delivery. He died in 1701, still unreconciled, and she put on formal widow’s mourning for him. The regime she built for herself after that would have impressed the Carmelites. Under the gowns she still wore in public, she wore a shirt of rough cloth against her skin, bracelets, garters, and a belt fitted with iron points turned inward that regularly opened wounds in her flesh.

She fasted constantly. Her money poured out into hospitals and charities. In 1693 she founded a hospice endowed to feed, house, and nurse a hundred poor women in perpetuity. A portrait of her from these years still hangs, painted as Mary Magdalene, the beautiful sinner weeping in the desert.

None of it bought her a single quiet night. The fear of death ruled her last years with a completeness that everyone around her observed. She could not bear darkness. She slept with her chamber blazing with candles, dozens of them, burning until morning.

She employed women whose entire job was to sit up around her bed through the night, awake, talking, playing cards, making noise. If she woke and found them drowsing, the distress was immediate. During these years she paid one visit that closes an old account. She went to the Carmelite convent and sat in the parlor grill with Sister Louise of Mercy, formerly Louise de La Vallière, the woman whose life she had walked over on her way up.

At some point Athénaïs offered to prepare a dish for her with her own hands. Louise accepted the kindness with one adjustment. She asked to be given the raw ingredients and cooked the dish herself. A nun in her sixties, three decades removed from the world, quietly declining to eat anything the marquise de Montespan had touched.

The end came at the spa town of Bourbon-l’Archambault in May of 1707. She was sixty-six years old and in apparently decent health. She paid her charitable pensions two years in advance and spoke as if squaring accounts. At Bourbon she fell suddenly and violently ill in the night.

She summoned her entire household into the sick room and made a public confession of her public sins, asking pardon aloud of everyone present for the scandal of her life. Then the terror that had kept her rooms burning bright for sixteen years simply left. She took the last sacraments with what witnesses called ardent piety, and met the actual arrival of the thing she had dreaded above everything calm. She died toward three in the morning on the 27th of May, 1707.

Her last word, the tradition says, was pardon. What happened to her body afterward reads like a final invoice from a century that had given her everything. Following custom for the great, the body was opened and divided for burial. The entrails traveled in a sealed urn entrusted to a local porter.

Somewhere on the road, the seal failed against the summer decomposition, and the smell overwhelmed the man. In his horror he tipped the contents into the roadside ditch and went on with the empty vessel. The viscera of the woman for whom Clagny rose and a king emptied treasuries went into a ditch in the Bourbonnais and stayed there. The news reached Versailles, and the king received the report with what Saint-Simon called perfect insensibility, a composure so total that his granddaughter-in-law could not hide her astonishment.

Louis explained himself with the coldest sentence in this entire story. Since he had dismissed her, he said, he had reckoned on never seeing her again, and so from that day she had been dead to him already. He then forbade their children to wear mourning. She had never legally been their mother.

Du Maine received the news and could scarcely conceal his joy. Her legitimate son raced to Bourbon, went through her papers, and was back at court within days. And in her apartments at Versailles, Madame de Maintenon, the widow Scarron, the governess, the wife who had spent forty years first serving this woman and then replacing her, heard that Athénaïs was dead, and to the bafflement of everyone who knew their history, wept and withdrew to hide the weeping, and stayed hidden a long while. Of everyone at that court, she may have been the only one still able to see all the way back to the beginning.

Two clever young women in a Paris salon, neither of them yet anything. Two years later, in 1709, an old king closed the file. La Reynie died that June, the policeman who had carried the affair in his head for thirty years. And with him gone, Louis sent for the records.

The bound dossier of the interrogations touching Madame de Montespan were brought from the archive to Versailles. And there, by the fireplace, the king went through them and fed them to the flames with his own hands, sheet after sheet, an afternoon’s methodical work. He believed he was ending the story. He missed the loose leaves, his own security procedure.

The order that the most dangerous testimony be kept on unbound sheets outside the official registers had left copies of exactly the worst material sitting in La Reynie’s personal working papers, which passed quietly with the rest of his files into the royal collections. They are in the Bibliothèque Nationale in Paris right now. Historians found it all in the nineteenth century and have been arguing about it ever since. In the pages a king spent thirty years and dozens of lives trying to unwrite, you can still find the conjuration to Astaroth and Asmodée in a clerk’s careful hand, and her name beside it.

He burned everything he could reach. The rest is still there.