In Assassin's Creed, what is the name of Desmond Miles's ancestor who lived during the Third Crusade?

Altaïr Ibn-La'Ahad is Desmond Miles's ancestor who lived during the Third Crusade in Assassin's Creed.

Altaïr is the central playable character in the first main Assassin's Creed game, released in 2007. The story places him in the Levant during the late 12th century, with major locations including Masyaf, Jerusalem, Acre, and Damascus.

The name Altaïr means “the flying one” in Arabic, while Ibn-La'Ahad means “son of no one.” He begins the game as a highly skilled but overconfident Assassin and is demoted after a failed mission. His master, Al Mualim, then assigns him targets whose deaths gradually expose a larger political conspiracy.

Altaïr is sometimes confused with Ezio Auditore, the protagonist of several later games. Ezio lived in Renaissance Italy, whereas Altaïr's storyline is set centuries earlier. The Animus allows Desmond to experience Altaïr's memories in the modern-day framing story.