In Assassin's Creed, Altaïr Ibn-La'Ahad's mentor is Al Mualim. Al Mualim leads the Assassin Brotherhood from Masyaf and initially serves as Altaïr's teacher, superior, and source of missions during the game's Crusades-era story.
Altaïr begins the game as an exceptionally skilled but overconfident Assassin. After a failed mission, Al Mualim strips him of rank and equipment, then sends him to eliminate targets in cities including Jerusalem, Acre, and Damascus. These assignments are meant to restore Altaïr's reputation while exposing a wider political conspiracy.
Al Mualim is a fictionalized version of Rashid ad-Din Sinan, a historical leader of the Syrian Nizari Ismaili community. The game adapts history rather than presenting a literal biography, placing its fictional Assassin Brotherhood among real Crusades-era figures and conflicts.
The name can be confused with Altaïr's later allies or enemies, but Al Mualim is specifically his mentor and the leader of the Masyaf Assassins at the beginning of the story.