Signs of a demoon invasion were believed to appear at Aix-en-Provence during the year 1609 through the victim Madeleine de Demandolx de la Palud. Madeleine, a 17-year-old Ursuline nun with a history of emotional instability, was returned often to the care of her parents to recover from attacks of depression. Father Louis Gaufridi was a friend of Madeleine's family and it is believed that he and Madeleine became lovers.
This rumor reached the ears of Sister Catherine de Gaumer, head of the Ursuline convent at Marseilles. She passed the rumor on to Madeleine's mother, and words were conveyed to Father Gaufridi that his attentions should cease immediately.
It was then that Madeleine was admitted to the Ursuline convent at Marseilles, under the direct supervision of Mother de Gaumer. To de Gaumer, Madeleine revealed the full story of her relations with Father Gaufridi. In order to prevent further damage and to halt any association with Father Gaufridi, Madeleine was transferred to the distant convent at Aix. Two years later, at the age of 19, Madeleine fell victim to what those around her considered to be unmistakable demonic possession; her body was contorted, and in a fit of rage she destroyed a crucifix.
Common convent practice at the time prescribed an exorcism to banish Madeleine's demons. Not only were the first attempts futile, but further attempts brought damning accusations that Father Gaufridi was a devil worshiper that had copulated with her since she was 17. Three more nuns were soon found to be possessed by demons, and by the end of the year that number had risen to eight. Sister Louise Capeau was considered to be the most extremely afflicted; her ravings and bodily contortions were more hideous than Madeleine's.
Father Gaufridi entered the courtroom after a series of physical and mental torture inflicted during his time in prison. His body had been shaved in a search for the Devil's Mark, three of which were found and used as evidence against him. A pact with the Devil was produced in court, allegedly signed by Gaufridi's own blood. A confession was also produced, which Gaufridi had signed in prison, extracted under torture. Included in the confession was an admission of celebrating a Black Mass in order to gain power over women.
April 30, 1611 was the day of Father Gaufridi's execution. With head and feet bare, a rope around his neck, Gaufridi officially asked pardon of God and was handed over to torturers. Still living after the torture of strapado and squassation, Gaufridi was escorted by archers while dragged through the streets of Aix for five hours before arriving at the place of execution. The priest was granted the mercy of strangulation before his body was burned to ashes.