Altaïr Ibn-La'Ahad is the Assassin's Creed protagonist commonly known simply as Altaïr.
Altaïr is the principal historical protagonist of the first Assassin's Creed game. His story takes place in 1191, during the Third Crusade, and follows his fall from favor, punishment by his mentor Al Mualim, and gradual restoration of his rank through a series of investigations and assassinations.
The name Ibn-La'Ahad is Arabic and is commonly translated as “son of no one.” Altaïr's narrative is tied to the early Assassin Order and to the Apple of Eden, a powerful artifact sought by both Assassins and Templars. His actions also influence the Brotherhood's later practices and philosophy.
Altaïr appears in other series material, including Assassin's Creed: Revelations, where Ezio discovers more about his life. He should not be confused with Desmond Miles, the modern-day descendant whose Animus sessions allow players to experience Altaïr's memories. Ezio, Arno, and Bayek are separate historical protagonists.