They would have preferred to have silenced this man forever; but now that he had gotten away and raised an objection, it would be necessary to dissolve the marriage by process of law, which would cause a great scandal.
Shortly after Sforza's flight a terrible tragedy occurred in the house of Borgia--the mysterious murder of the Duke of Gandia.

On the failure of Alexander's scheme to confiscate the estates of the Orsini and bestow them on his dearly beloved son, he thought to provide for him in another manner.

He made him Duke of Benevento, thereby hoping to prepare the way for him to reach the throne of Naples.

A few days later, June 14th, Vannozza invited him and Caesar, together with a few of their kinsmen, to a supper in her vineyard near S.Pietro in Vinculo.

Don Giovanni, returning from this family feast, disappeared in the night, without leaving a trace, and three days later the body of the murdered man was found in the Tiber.
According to the general opinion of the day, which in all probability was correct, Caesar was the murderer of his brother.