Who is the main historical protagonist of the original Assassin's Creed?

Altaïr Ibn-La'Ahad is the main historical protagonist of the original Assassin's Creed. He is a Syrian Assassin operating during the Third Crusade in 1191, and the player controls him throughout the game's historical sequences.

Altaïr begins the story as a highly ranked but overconfident member of the Assassin Brotherhood. After failing to secure an important artifact, he is demoted by his mentor, Al Mualim, and must eliminate targets in several major cities to restore his status. These missions gradually reveal a wider Templar conspiracy.

Altaïr is sometimes confused with Ezio Auditore, the protagonist of Assassin's Creed II, Brotherhood, and Revelations. Altaïr also appears in later franchise stories, especially Revelations, but he is not the protagonist of those games. His role in the first title made him the character who established the series' original historical perspective.