What is the name of the main Assassin in the original Assassin's Creed?

Altaïr Ibn-La'Ahad is the main Assassin in the original Assassin's Creed.

Altaïr is the playable historical protagonist of the 2007 game. His name is Arabic and is commonly translated as “The Flying One, Son of No One.” At the beginning of the story, he is an accomplished but arrogant member of the Assassin Brotherhood operating during the Third Crusade.

After a failed mission causes him to lose his rank and equipment, Altaïr is ordered by his mentor, Al Mualim, to eliminate a series of targets. These missions take him through Jerusalem, Acre, and Damascus while he investigates a conspiracy involving the Templars and the Apple of Eden.

Altaïr is sometimes confused with Ezio Auditore because Ezio became the most prominent early-series protagonist, appearing in Assassin's Creed II, Brotherhood, and Revelations. Altaïr later returns as a major character in Assassin's Creed Revelations, but he is the central Assassin of the first game.