The Laboratory of La Voisin
The Laboratory of La Voisin

The court of the Sun King Louis XIV was known as a gallant place where beautiful ladies with flexible morals were able to calculate chances of promotion quite the way up to the most exalted beds in the country. Competition, however, was fierce and various ladies with respectable charms but little patience turned to strategies destined to improve their pecuniary as well as social conditions in the shortest possible time.

One of these hungry ladies was Marie Madeleine Marguerite d’Aubray, from an equally rich and famous noble family. At the age of 21 (1651), she married the Marquis Antoine Gobelin de Brinvilliers, a wealthy Flemish wool merchant, with whom she had five children. Through her husband she met the flimsy, but charming – and permanently mired in financial difficulties – scoundrel Monsieur Godin de Sainte-Croix, with whom she began a prolonged affair.

Marie’s father considered the affair, did not like it, and managed to send the friend of the family for a year to the Bastille prison, where the hobby alchemist Sainte-Croix  obviously met an inmate colleague who taught him various skills on toxicology. At liberty again, Sainte-Croix returned straight back to his lover, with specific proposals on how the sweetheart could take possession of the family heritage quickly. In the way, unfortunately, stood her father and two brothers and a sister with whom she would have to share the heritage.

The brothers expired mysteriously in the course of the summer of 1670 , but the suspicious Sister Thérèse d’Aubray now developed a strong interest in checking her food  and thus remained alive, although she died before the subsequent trial and condemnation of her dear sister, probably due to natural causes. Although the autopsies of the brothers evidenced certain indications of poisoning, Marie always had an alibi and the servant of the brothers in question, a certain Jean Stamelin called La Chaussee ( “the Way”), was above suspicion.

It came out by accident only.  Sainte-Croix died in a failed experiment in his laboratory, probably by inhaling toxic gases. Since he, as always, was heavily in debt, his estate had to be executed at the local court, where a cassette was noticed and opened, which divulged not only his promissory notes, but also a variety of poisons as well as the lovers‘ full correspondence.

The search of Sainte-Croix’s cassette

The subsequent investigation quickly led to the arrest of the servant, his trial, torture and execution, while Marie fled abroad, first to England, then to Liège – into a convent. After her extradition, she  was subjected to the water torture (see cover photo), then various other gymnastic exercises and finally sentenced to death on the scaffold on July 16, 1676 . So far so good.

Clerical and secular interrogations and torture of Mme. Brinvilliers

Meanwhile, a series of strange deaths of rich nobleman – or at least gossip about it – had aroused the idle suspicion of the court. What advanced the subject to the favourite theme of the courtiers’ natter was the strange fact that Louis Henri de Pardaillan de Gondrin , Marquis de Montespan, began to complain publicly about his wife Françoise de Rochechouart de Mortemart, Marquise de Montespan, who – under her artist or bed name Athénaïs – had replaced Louise de La Valliere, the official mistress of Louis XIV, in the royal four-poster bed. Even more shocking, he accused the First Lady-in-Waiting of Queen Marie Therese, Mme. Julie d’Angennes to have arranged the connection for selfish motives.

Louise de la Vallière
Louise de la Vallière
Portraits of the Marquise de Montespan, mistress of Louis XIV

The problem  was that – usually – the husbands of the royally selected ladies did not complain about matters they could not change, but tried to draw from the circumstances given the best possible benefits for their own careers. But Montespan was so angry that he not only publicly demanded a duel with the king but also decorated Louis‘ coach with antlers, for which he was promptly jailed. He was subsequently exiled, but did not give up. Although prohibited by order of the king,  he travelled not only to Paris each summer from 1670 to 1686, but also paid for an annual requiem mass for his (quite lively) wife, and forced the two children to participate in a phony funeral.He also announced publicly and repeatedly that his wife had swayed the king with love potions and black masses.


A Catholic monarch could – of course – not sit out such accusations, whether Mme. Montespan had born him seven children or not. Thus, the Marquis fell even deeper in disgrace and the irritated King sent his bloodhounds out for him.

But Louis needed a pretext to make it not look like a personal pursuit – which of course it was. Because in the wake of sensational trial of Mme. Brinvilliers, all the hallways of the court echoed with rumours of poisonings anyway, he created an official commission and special court, a renewed Chambre Ardente, which had already served his blessed colleagues Francis I, Henry II and Francis II so well in the pursuit of heretics. Fittingly, this time it was called Cour de Poison ( “Poison Court”).

For a change, the official task of the court this time was combating the suspected circles of Satanism – the popular assumption was that the cult urged his followers to commit the suspected murders by poison (financial interests were officially taboo). The usual suspects were mostly women – but not only; psychics, spiritualists, pharmacists, poisoners and manufacturers of love potions.

The French police prefect Gabriel Nicolas de la Reynie was commissioned to destroy the satanic conspiracy. About four hundred suspects were interrogated and by the enthusiastic use of torture numerous enjoyable confessions were obtained. Everyone accused everybody else, it was a lark.

Philip of Orleans. the brother of Louis XIV, meets the devil himself during a party at La Voisin, Catherine Deshayes
Philip of Orleans. the brother of Louis XIV, meets the devil himself during a party at La Voisin, Catherine Deshayes

But suddenly there was a true lead. A thin trail of the king‘s mistress to a suspected mass murderess and poisoner could be established, the famous La Voisin (also called “Monvoisin” or “Montvoisin”), a person Reynie had noticed before. In the case of Mme. Montespan who was, after all, the official royal mistress, the chief of police suspected not really poison, but the acquisition of love potions to ensure the king’s favour, he thought quite possible – Black Masses might be required for their production  – who knew?

Catherine Monvoisin (or Montvoisin), née Deshayes, usually called "La Voisin"
Catherine Monvoisin (or Montvoisin), née Deshayes, usually called “La Voisin”

In the course of his investigation Reynie had busted two soothsayers, who accused Mme. Monvoisin. The lady turned out to be a winner. It could be determined – reasonably reliable – that she had a customer base that actually reached into high nobility.

Inquiries in the vicinity of the bustling dame rendered quickly that she was perceived to provide horoscopes and black magic, actually sold poisons and love spells and performed abortions as well. In her garden stood a chapel in which demons like Astaroth and Asmodeus were worshiped. These black masses were visited by an illustrious clientele of courtiers and princesses – even the executioner of Paris himself belonged to the circle. Embarrassingly, one of the carriages waiting outside bore the coat of arms of the royal mistress and soon the police could prove visits by Mme. Montespan all the way back to 1665.

Illustration from “Justine” by the Marquis de Sade

Claimed by several witnesses in the subsequent interrogations was that in these ceremonies Madame de Montespan had lain naked on an altar while her petitions for the king’s continuing favour were passed on to the Christian God and the gods of the underworld. She had allowed the priest Guibourg to introduce a host in her vagina and to have intercourse with her while praying. [ Description of the exhibition ] [ PDF ] The daughter of Monvoisin confirmed both the masses and the sales of love potions, but these statements were immediately relegated to the secret archives.

Catherine Monvoisin and the priest Étienne Guibourg performing a Black-Mass on the mistress of King Louis XIV of France, Madame de Montespan - by Henry de Malvost, 1895
Catherine Monvoisin and the priest Étienne Guibourg performing a Black-Mass on the mistress of King Louis XIV of France, Madame de Montespan – by Henry de Malvost, 1895

It became worse soon. Excavations on the site of La Monvoisin unearthed the remains of more than 2,500 aborted, dead-, early- or newborn babies.

Execution of La Voisin
Execution of La Voisin

That Mme Monvoisin was due, was clear – but first royal generosity had to protect the innocent, that is noble, attendees of the masses – their names were removed from the lists, and they were advised to take extensive vacations – preferably abroad.

Madame de Sevigne witnessed the execution of La Voisin and wrote in her letters: “At Notre Dame she refused to apologize, and fought tooth and nail at the Place de la Greve. They brought her to the pile of wood, tied her up in a sitting position with iron chains and covered her with straw. She cursed without pause and repulsed the straw five or six times, but eventually the fires flared up, and she was never seen again. Her ashes are now flying around in the air. Thus died Mrs Voisin, famous for her crimes and pagan unbelief. “[ Source ]

Another mistress of Louis and rival of Montespan, the beautiful Marie Angélique de Scoraille de Roussille (see above), also died suddenly. Rumours concentrated on Mme. De Montespan and Reynie actually investigated her. But several influential courtiers prevented an indictment, including Françoise d’Aubigné,Marquise de Maintenon, usually called Madame de Maintenon, the governess of the royal children (with whom Ludwig later entered into a secret, morganatic marriage),. But after the death of the beautiful Angélique, Montespan quickly fell out of favour.

Françoise d'Aubigné, Marquise de Maintenon (1635-1719)
Françoise d’Aubigné, Marquise de Maintenon (1635-1719)

Slowly the poison affair fizzled out – the last execution took place in 1683. Reynie was urged to complete his investigation – he probably got too close to some folks dear to the royal well-being. What remained was a new law regulating the marketing of poisons, which became a model worldwide. Divination and soothsaying was banned in France and a decree of 1682 ended witch trials.

From 1686 on Ludwig was rather busied by the formation of the League of Augsburg , and through the wars of the Palatinate – and later the Spanish Succession , and the affairs of the court lost importance. The King spent his subsequent years more and more with the Marquise de Maintenon and in the bosom of his family.

Louis XIV with Mme. de Maintenon and family, attributed to Nicolas de Largillière
Louis XIV with Mme. de Maintenon and family, attributed to Nicolas de Largillière

(© John Vincent Palatine 2019)

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