In the first Assassin's Creed game, what is the name of the protagonist controlled by the player?

The protagonist controlled by the player in the first Assassin's Creed game is Altaïr Ibn-La'Ahad.

Altaïr is a Syrian Assassin active during the Third Crusade in 1191. The game follows his fall from grace after a failed mission, his demotion within the Brotherhood, and his efforts to regain his rank by carrying out targeted assassinations.

His name is sometimes confused with that of Desmond Miles, the modern-day character whose genetic memories allow players to experience Altaïr's life through the Animus. Altaïr is the historical character being relived, while Desmond is the descendant and modern protagonist.

Altaïr later becomes an important figure in Assassin history. His story continues in Assassin's Creed: Revelations, which explores his later life and his role in preserving the Brotherhood's knowledge.