Which Ubisoft studio led development of the original Assassin's Creed?

Ubisoft Montreal led development of the original Assassin's Creed.

The Montreal studio developed the first game for Ubisoft, which released in 2007. Its team created the open-world historical environments, climbing and parkour systems, stealth assassinations, and Animus framing device that established the franchise's identity.

The project grew from work related to Prince of Persia: The Sands of Time. Ubisoft Montreal's developers explored a concept involving a protective figure and an important leader, eventually reshaping the idea into the Assassin-focused world of the new series.

Other Ubisoft studios later led major entries. Ubisoft Quebec developed Assassin's Creed Odyssey and Assassin's Creed Syndicate, while Ubisoft Sofia worked on Assassin's Creed Rogue. Their involvement does not change Montreal's lead role in the original game.