In 1611 a group of conspirators, nobles from Modena and Mantua, was accused of devising a plot to assassinate Ranuccio I Farnese, Duke of Parma and other members of the Farnese family in Parma. In reality, the plot had been ""uncovered"" when a prisoner (being held for unrelated crimes) confessed to it and implicated members of various noble houses. Though the accusations were likely untrue, 100 of the ""conspirators"" were tortured and eventually executed in Parma's main square in 1612. Many of their estates were confiscated leaving a large number of now legitimately discontented nobles. Until his death in 1622, Ranuccio remained paranoid about future assassination attempts and about curses from witches and heretics. He persecuted "witches" and alleged conspirators savagely and even had his own mistress, Claudia Colla, burned to death. He remained convinced that other noble families were plotting his downfall.