In the original Assassin's Creed game, the player controls Altaïr Ibn-La'Ahad during the main historical storyline.
Altaïr is a Syrian Assassin operating in the Holy Land during 1191, at the time of the Third Crusade. The game follows his missions in cities including Masyaf, Jerusalem, Acre, and Damascus. After Altaïr breaks the Assassin Brotherhood's code, his mentor Al Mualim reduces his rank and sends him on a sequence of assignments designed to restore his status.
Altaïr's story is framed by a modern plot involving Desmond Miles and the Animus, a machine that lets users experience genetic memories. This structure is why the game contains both medieval missions and modern-day scenes. Altaïr is sometimes confused with Ezio Auditore, who became the central playable Assassin in Assassin's Creed II, the 2009 sequel.
The character also appears in later series material, including Assassin's Creed: Revelations, which links his life more closely with Ezio's. His name is commonly rendered with a variety of English spellings, but Altaïr Ibn-La'Ahad is the standard form used for the original protagonist.