In the first Assassin's Creed game, which Assassin does the player control during the Third Crusade?

In the first Assassin's Creed game, the player controls Altaïr Ibn-La'Ahad during the Third Crusade.

Altaïr is introduced as a highly skilled but overconfident member of the Assassin Brotherhood. After failing an important mission, he is demoted and must regain his rank by investigating targets in cities including Masyaf, Damascus, Acre, and Jerusalem. The game presents these events through the Animus, a fictional device that lets Desmond Miles experience his ancestors' memories.

The historical setting is the late 12th century, during the Third Crusade. Altaïr's story combines fictional Assassin activity with real medieval locations and figures, although the plot itself is not a literal account of history. His name is sometimes shortened to Altaïr, while the full Arabic name is Altaïr Ibn-La'Ahad. He is not the protagonist of Assassin's Creed II, which follows Ezio Auditore in Renaissance Italy.

Altaïr later appears in expanded Assassin's Creed stories, including Assassin's Creed: Revelations, where his life and legacy are connected to Ezio's journey.