The 2007 video game Assassin's Creed is the first main installment in the Assassin's Creed series.
Ubisoft developed the game, while Ubisoft Montreal led production. It introduced players to Altaïr Ibn-La'Ahad, an Assassin operating during the Third Crusade. The story alternates between Altaïr's historical missions and Desmond Miles's experiences in the modern day.
The game established several features that became central to the franchise: social stealth, investigation missions, parkour across historical cities, hidden blades, and the Animus, a machine that accesses genetic memories. Its major settings include Jerusalem, Acre, and Damascus.
Assassin's Creed II followed in 2009 and shifted the focus to Ezio Auditore da Firenze. Later games expanded the series into different historical periods, but the original title remains the starting point for the main series. It is sometimes confused with the 2007 short film Assassin's Creed: Lineage, which was released later as a prequel promotion for the second game.