The protagonist of the original Assassin's Creed game is Altaïr Ibn-La'Ahad.
Altaïr is a Syrian Assassin operating in the Holy Land during the Third Crusade, around 1191. The game follows his fall from grace after a failed mission and his gradual restoration of rank under the guidance of his mentor, Al Mualim.
The name is sometimes written as Altaïr or Altair, while Ibn-La'Ahad is his family name. He is not the same character as Ezio Auditore, the Italian Assassin who leads the next major trilogy of games.
Altaïr also appears in later series lore, including Assassin's Creed: Revelations, where his life and legacy are explored through memories experienced by Ezio. His hidden blade, investigations, and encounters with historical figures established many of the series' signature elements.