Ezio's surname is Auditore; he is Ezio Auditore da Firenze, the central protagonist of Assassin's Creed II.
Ezio begins his story as a young nobleman in Florence in the late 15th century. A family tragedy draws him into the conflict between the Assassin Brotherhood and the Templar Order. Across the trilogy, he develops from an inexperienced avenger into a major Assassin leader.
His main saga includes Assassin's Creed II, Brotherhood, and Revelations. These games follow him through Florence, Venice, Rome, and Constantinople, covering decades of his life. His story also connects him with Altaïr through the Masyaf library and with Desmond Miles through the Animus.
The name is sometimes shortened to “Ezio,” but “Auditore” identifies his family. “Da Firenze” means “of Florence” and reflects his association with the city; it is not a separate protagonist surname. Ezio is also distinct from later Italian characters such as Arno Dorian, whose story is set in revolutionary Paris.