In 1321, Renato was aboard his father's trading vessel when it was ransacked by pirates under the employ of the Templar Order, who sought the Codex of Altaïr Ibn-La'Ahad that was in his father's possession. After his mother's murder, Renato and his father were thrown from the vessel.
The two managed to reach the shore alive, and the next day they happened upon the corpse of Renato's mother. Traveling by land, they made their way back to Florence, and Domenico rented a small room for his son by using Marco Polo's bank account. From there, Renato and Domenico traveled to Venice, where Domenico set off to meet with his father and his patron.
Once Domenico had returned, Renato and his father adopted the name of "Auditore", impersonating a Florentine noble, and successfully integrated themselves as a part of the city's nobility.
- Renato's name came from the Italian, Portuguese, and Spanish variant of the Latin name Renatus, meaning "born again."
- Although never explicitly named in Assassin's Creed II, Renato was identified as the grandfather of Giovanni Auditore da Firenze in the dossiers handed to employees of Abstergo Industries, during the second stage of the Animi Training Program.