Beatrice was the daughter (by his first wife) of Francesco Cenci, a vicious and violent Roman nobleman of great wealth and influence. In 1595 he took his second wife, Lucrezia, with Beatrice, to the lonely castle of La Petrella, in the province of Aquila, imprisoning them there and treating them with great brutality. After various attempts to gain her freedom, Beatrice found refuge in a liaison with the castellan, Olimpio Calvetti.

With Calvetti, her brother Giacomo, and others, she finally planned the murder of her father. He was assassinated on Sept. 9, 1598, and his body thrown from a balcony to create the appearance of an accident. The facts, however, soon came out, and the whole Cenci family was arrested. Lucrezia, Giacomo, and Bernardo, another brother, confessed the crime, and Beatrice, who at first denied everything, even under torture, also ended by confessing. Great efforts were made to obtain mercy for the accused, but Clement refused to grant pardon and Beatrice, Lucrezia, and Giacomo were executed, Bernardo escaping death because of his youth. The Cenci property was confiscated, and this, it was rumoured, was the pope's object in destroying them.