The Affair of the Poisons (L'affaire des poisons) was a major murder scandal in France which took place in 1677–1682, during the reign of King Louis XIV of France. During it, a number of prominent members of the aristocracy were implicated and sentenced on charges of poisoning and witchcraft. The scandal reached into the inner circle of the king. It led to the execution of 36 people.
The origin of the case began in 1675 after the trial of Madame de Brinvilliers, who was accused of having conspired with her lover, army captain Godin de Sainte-Croix, to poison her father Antonine Dreux d'Aubray in 1666 and two of her brothers, Antoine d'Aubray and François d'Aubray, in 1670, in order to inherit their estates. There were also rumours that she had poisoned poor people during her visits in hospitals. After being accused she fled, but was arrested in Liège. Brinvilliers was tortured and confessed, was sentenced to death, and on 17 July was tortured with the water cure (forced to drink sixteen pints of water), beheaded, and her body burned at the stake. Her alleged accomplice Sainte-Croix did not face charges because he had died of natural causes in 1672.
The sensational trial drew attention to a number of other mysterious deaths, starting a number of rumours. Prominent people, including Louis XIV, became alarmed that they might be poisoned.
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.