Who is Altaïr Ibn-La'Ahad's mentor in the first Assassin's Creed?

Al Mualim is Altaïr Ibn-La'Ahad's mentor in the first Assassin's Creed.

Al Mualim leads the Assassin bureau at Masyaf, a mountain settlement in the Levant. After Altaïr violates Assassin protocol during a mission, Al Mualim strips him of his rank and equipment. He then sends Altaïr to eliminate a series of targets, allowing the young Assassin to regain his status while investigating a wider conspiracy.

The name Al Mualim means “the teacher” in Arabic, and the character initially serves as Altaïr's authority figure and instructor. His relationship with Altaïr changes as the investigation reveals that the mentor is pursuing the Apple of Eden for his own purposes.

Al Mualim is not one of the nine principal targets Altaïr is ordered to assassinate at the start of the game. He is the leader who assigns those missions and later becomes central to the game's final confrontation. Robert de Sablé is a Templar grand master, not Altaïr's mentor.