Al Mualim is the Assassin Brotherhood leader who mentors Altaïr in the first Assassin's Creed. He serves as the master of the Masyaf bureau and directs Altaïr after the protagonist's failed mission causes him to lose his rank.
Al Mualim sends Altaïr to investigate and assassinate nine targets connected to the Templars. The assignments take Altaïr to Jerusalem, Acre, and Damascus, while each completed mission reveals more about the political and ideological conflict.
The name is also associated with the historical Rashid ad-Din Sinan, a leader of the Nizari Ismailis in Syria during the medieval period. The game draws on that historical association but creates its own fictional plot, characters, and supernatural artifacts.
Al Mualim's role changes significantly as the story approaches its conclusion. He is not simply a mission-giver, which is why identifying him only as Altaïr's mentor leaves out a major part of the game's narrative reveal.