The original Assassin's Creed game features Altaïr Ibn-La'Ahad as its playable Assassin during the Third Crusade.
Altaïr is introduced as a highly skilled but arrogant member of the Assassin Brotherhood. After failing a mission, he is stripped of his rank and weapons by his mentor, Al Mualim, and must regain his status by carrying out a sequence of assassination missions.
The game takes place mainly in 1191, with major historical locations including Jerusalem, Acre, and Damascus. Altaïr's story is presented through the Animus, a device that lets modern people experience genetic memories from their ancestors.
Altaïr is sometimes confused with Ezio Auditore, the protagonist of Assassin's Creed II and its related games. Altaïr also appears in later entries, especially Assassin's Creed: Revelations, which connects his life with Ezio's story.