The affair proper opened in February 1677 after the arrest of
Magdelaine de La Grange on charges of forgery and murder. La Grange appealed to
François Michel Le Tellier, Marquis of Louvois, claiming that she had information about other crimes of high importance. Louvois reported to the king, who told
Gabriel Nicolas de la Reynie, who, among other things, was the chief of the Paris police, to root out the poisoners. La Reynie sought to calm the king. The subsequent investigation of potential poisoners led to accusations of witchcraft, murder and more. Authorities rounded up a number of
fortune tellers and
alchemists who were suspected of selling not only
divinations,
séances and
aphrodisiacs, but also "inheritance powders" (a euphemism for poison). Some of them confessed under torture and gave authorities lists of their clients, who had allegedly bought poison to get rid of their spouses or rivals in the royal court. The most famous case was that of the midwife Catherine Deshayes Monvoisin or
La Voisin, who was arrested in 1679 after she was incriminated by the poisoner
Marie Bosse. La Voisin implicated several important courtiers. These included
Olympia Mancini, the Countess of Soissons, her sister, the
Duchess of Bouillon,
François Henri de Montmorency, Duke of Luxembourg and, most importantly, the king's mistress,
Madame de Montespan. Questioned while intoxicated, La Voisin claimed that Montespan had bought aphrodisiacs and performed
black masses with her in order to gain and keep the king's favour over rival lovers. She had worked with a priest named
Étienne Guibourg. There was no evidence beyond her confessions, but bad reputations followed these people afterwards. Eleanor Herman, in her book
Sex with Kings (2009), claims that the police, given reports of "babies' bones", uncovered the remains of 2,500 infants in La Voisin's garden. However, Anne Somerset disputes this in her book
The Affair of the Poisons (2003) and states there is no mention of the garden being searched for human remains. Also involved in the scandal was
Eustache Dauger de Cavoye, the eldest living scion of a prominent noble family. Cavoye was disinherited by his family when, in an act of debauchery, he chose to celebrate Good Friday with a black mass. Upon his disinheritance, he opened a lucrative trade in "
inheritance powders" and aphrodisiacs. He mysteriously disappeared after the abrupt ending of Louis's official investigation in 1678. Because of this and his name, he was once suspected of being the
Man in the Iron Mask. However, this theory has fallen out of favour because it is now known that he was imprisoned by his family in 1679 in the
Prison Saint-Lazare. == The end of the trial ==