These facts show how closely and how long the Porcaro were allied to the Borgias.
This Roman family had been made famous in the history of the city by the fate of Stefano, Cola di Rienzi's successor.

The Porcaro claimed descent from the Catos, and for this reason many of them adopted the name Porcius.

Enjoying friendly relations with the Borgias, they claimed them as kinsmen, stating that Isabella, the mother of Alexander VI, was descended from the Roman Porcaro, who somehow had passed to Spain.

The similarity of sound in the Latin names Borgius and Porcius gave some appearance of truth to this pretension.
Next to Antonio, Hieronymus Porcius was one of the most brilliant retainers of the house of Borgia.

Alexander, upon his election to the papal throne, made him auditor of the Ruota (the Papal Court of Appeals).