Which developer led production of the original 2007 Assassin's Creed game?

Ubisoft Montreal led production of the original 2007 Assassin's Creed game.

Ubisoft Montreal developed the first Assassin's Creed, with Ubisoft publishing it for PlayStation 3 and Xbox 360 in November 2007. The studio established the series' core combination of historical settings, freerunning, social stealth, assassination missions, and a modern-day framing story.

The game follows Altaïr Ibn-La'Ahad during the Third Crusade, while Desmond Miles experiences Altaïr's memories through the Animus. Its cities, including Jerusalem, Acre, and Damascus, helped define the franchise's emphasis on reconstructed historical environments.

Later Assassin's Creed games were led by other Ubisoft studios, which can create confusion when identifying the developer. Ubisoft Quebec led Assassin's Creed Odyssey and Syndicate, while Ubisoft Sofia worked on Liberation and other projects. Ubisoft Montreal remained a major Assassin's Creed studio, but the specific answer for the original game is Ubisoft Montreal.