In Assassin's Creed, Altaïr Ibn-La'Ahad's mentor before his betrayal is Al Mualim.
Al Mualim is the leader, or Mentor, of the Assassin Order in the game's 1191 storyline. He directs Altaïr's missions from the fortress of Masyaf and appears to be the authority guiding the younger Assassin back toward discipline after Altaïr breaks the Order's rules.
The name means “the teacher” in Arabic, which suits the character's role and also foreshadows the game's central deception. Al Mualim eventually reveals that he has been manipulating events and seeks control of the Apple of Eden, a powerful Piece of Eden.
Players sometimes confuse Al Mualim with the historical Rashid ad-Din Sinan, the real Nizari leader associated with Masyaf. The game draws on that historical figure but presents a fictionalized version within its alternate-history plot.