Acquetta di Novellara

Matilda d'Este, the daughter of Sigismund Francis d'Este (Sigismund IV, 1647-1732, a descendant of Sigismund d'Este), Marquis of St. Martin, and Teresa Maria Grimaldi (1648-1723) of Monaco, married Camillo III Gonzaga, Count of Novellara in 1695.

She is famous for creating an arsenic-based poison, known as "acquetta di Novellara", which she used to get rid of her enemies.

After learning that her husband had become infatuated with Orsola Manari, Matilda tried to have him killed by two hired killers who, June 8, 1714, fired some harquebus shots at his carriage as he was leaving the castle. The Count escaped unhurt, but as a punishment, and in order to avoid any scandal, he sent Matilda back to her father, keeping their children with him. Matilda returned to Novellara just eleven years later for the christening of her grand-daughter Maria Teresa, Ricciarda’s daughter (according to what was written by the canon Vincenzo Davolio in his Memorie Storiche della Contea di Novellara - Historical Memories of the County of Novellara).