In the first Assassin's Creed game, Al Mualim is the Masyaf-based Assassin leader who guides Altaïr.
Al Mualim is introduced as the mentor and superior of Altaïr Ibn-La'Ahad, the game's central Assassin. His headquarters is the mountain fortress of Masyaf, which serves as the main Assassin settlement in the 12th-century storyline. After Altaïr breaks the Brotherhood's rules during an early mission, Al Mualim removes his rank and equipment before sending him on a series of missions to regain his status.
The name is also a title rather than a conventional personal name: “al-mu'allim” means “the teacher” or “the master” in Arabic. That wording reflects his role within the fictional Brotherhood. Players sometimes confuse him with Malik Al-Sayf, another important Assassin who becomes a bureau leader in Jerusalem.
Al Mualim's position gives him influence over the game's early plot, but his relationship with Altaïr changes dramatically as the story approaches its conclusion.