Which Assassin's Creed game introduced Renaissance hero Ezio Auditore?

Assassin's Creed II introduced the Renaissance hero Ezio Auditore.

Released in 2009, the game follows Ezio from his youth in Florence into his transformation as an Assassin. Its historical narrative spans several decades of fifteenth-century Italy and includes locations such as Florence, Venice, Forlì, and the Tuscan countryside.

Ezio begins as a nobleman whose family is caught in a political conspiracy. After the deaths of his father and brothers, he pursues the people responsible and gradually learns about the Assassin Brotherhood. Leonardo da Vinci helps him interpret coded designs and improve equipment.

The game expanded the original formula with economic management, a larger range of weapons, and more developed supporting characters. Ezio’s story continues directly in Assassin's Creed: Brotherhood and Assassin's Creed: Revelations, making him the franchise’s most extensively explored protagonist.