Which Assassin's Creed game introduced the recurring character Ezio Auditore?

Assassin's Creed II introduced the recurring character Ezio Auditore.

The sequel opens in fifteenth-century Florence and follows Ezio from his youth into his development as an Assassin. His family is caught in a political conspiracy, and the resulting personal loss sends him on a long campaign across Renaissance Italy.

Ezio later returns as the protagonist of Assassin's Creed: Brotherhood and Assassin's Creed: Revelations. Brotherhood continues his story mainly in Rome, while Revelations follows his later life in Constantinople and connects his narrative with Altaïr's legacy.

The distinction matters because Brotherhood and Revelations are sometimes remembered as the character's first appearance due to their strong focus on him. However, Ezio's debut occurs in Assassin's Creed II, released in 2009. Assassin's Creed III instead introduces Connor Kenway as its principal historical protagonist.