In Assassin's Creed, Altaïr Ibn-La'Ahad's mentor and former master is Al Mualim.
Al Mualim leads the Assassin Order from Masyaf during the events of the first game. His title means “The Teacher” in Arabic, reflecting his authority over the Assassins and his role in training Altaïr.
Altaïr begins the story as a highly skilled but arrogant Assassin. After a failed mission, Al Mualim demotes him and assigns him a series of targets. These missions are presented as a path to restoring Altaïr's rank, but they also expose a larger conflict involving the Templars and the Apple of Eden.
A common mix-up is confusing Al Mualim with Rashid ad-Din Sinan, the historical leader who inspired the character. The game uses historical names and settings, but its story is fictionalized and includes its own mythology, technology, and characters.