The Poisoner Of The Sun King's Court

In the glittering Paris of Louis XIV — the Sun King, the palace of Versailles, the most refined court in Europe — there was a thriving trade in murder, and its most famous practitioner was a woman named Catherine Monvoisin, known to everyone as La Voisin. On the surface she was a fortune-teller and a beauty specialist, a plump, cheerful woman who told noblewomen their futures and sold them face creams and love charms. Underneath, she ran one of the most notorious criminal enterprises in French history. The women of the court came to her with a particular kind of problem. A husband who would not die. A rival who held a lover’s attention. A king’s affection that was drifting elsewhere. La Voisin had a solution for each. For the husband, there was poison — she was part of a loose network of fortune-tellers and alchemists who dealt in arsenic-based “inheritance powders,” so called because they turned wives into wealthy widows. For the wandering lover, there was magic: love potions, charms, and — for the most desperate and highest-paying clients — the black mass.

The Horror

When the scandal finally broke, in what became known as the Affair of the Poisons, the details that emerged were so appalling that Louis XIV set up a special secret court, the Chambre Ardente or “Burning Chamber,” to investigate. Its testimony described a Paris underworld of poisoners, sorcerers and renegade priests. La Voisin, the investigators heard, arranged black masses in which a defrocked priest named Étienne Guibourg would say a blasphemous parody of the Mass — over the naked body of the client, used as a living altar. Blood was involved. And, according to the confessions extracted, infants were sacrificed in these rites, their throats cut, their bodies burned or discarded. When investigators searched the grounds of La Voisin’s house, it was reported that the remains of a great many babies — the numbers claimed run into the thousands, and are certainly exaggerated, but the graves were real — were found buried in her garden and around her property. They were said to be the stillborn, the unwanted, and the newborns of desperate women, funnelled into her rituals. What made the affair a catastrophe for the crown was who her clients turned out to be. The trail led upward through the aristocracy and, most explosively, to Madame de Montespan — the king’s own chief mistress, mother of several of his children. Under interrogation, witnesses claimed that Montespan had been a customer for years, buying love magic to keep the king’s affection and, it was alleged, even commissioning black masses and once considering poisoning the king or a rival. Whether the accusations against Montespan were true or the product of torture and score-settling is still argued by historians; what is certain is that Louis XIV was horrified enough to bury that part of the investigation. Some records were destroyed. Montespan was never charged. The king protected his court from its own reflection. La Voisin herself had no such protection. She was arrested in 1679, interrogated, and convicted of witchcraft and poisoning. On the night before her death she reportedly ate and drank heavily and sang obscene songs, raging and cursing. On 22 February 1680, she was taken to the Place de Grève — the great execution square in front of the Paris city hall, the same place where so many were broken and burned across the centuries. She fought the whole way. Accounts describe her struggling against the straw and the ropes, swearing at the crowd, trying to shove the kindling away with her feet. She was tied to the stake and burned alive before a large audience. The refined city that had bought her poisons watched her die for selling them. The Affair of the Poisons rolled on. Dozens were arrested; thirty-six were executed. Others were imprisoned for life or exiled. It exposed the ugly secret beneath the silk of the Sun King’s court: that behind the manners and the music, wives were quietly murdering husbands and rivals were quietly murdering rivals, and a cheerful woman in a Paris side-street was supplying the means.

The Modern Relic

The Place de Grève still exists — it is now the Place de l’Hôtel de Ville, the square in front of Paris City Hall, one of the busiest public spaces in the city, where Parisians and tourists cross every day over ground that was for centuries the city’s place of public execution. The records of the Chambre Ardente survive in the French archives and remain a primary source for one of the strangest criminal scandals in European history. And Madame de Montespan’s fall from favour — she was quietly eased out of the king’s bed in the years that followed — is written into the history of Versailles, the palace you can still walk through, where the whole affair began as court gossip and ended in fire. The detail that stays with you is the ordinariness of the demand. These were not monsters coming to La Voisin. They were fashionable women with a husband problem, and there was a woman across town who, for a fee, could make the problem disappear.

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