Who developed Assassin's Creed III as its lead studio?

Ubisoft Montreal developed Assassin's Creed III as its lead studio.

Ubisoft Montreal led production of the 2012 mainline game, which introduces Connor, or Ratonhnhaké:ton, during the American Revolutionary War. The studio had also led development on earlier major Assassin's Creed titles, including the original game and Assassin's Creed II.

Assassin's Creed III uses the AnvilNext engine and expands the series with frontier environments, hunting, naval missions, and a new modern-day phase for Desmond Miles. Its historical story moves through locations such as Boston and New York and includes figures connected to the Revolution.

Ubisoft Quebec later became the lead studio for Assassin's Creed Syndicate and Assassin's Creed Odyssey. Ubisoft Sofia led development of Assassin's Creed Rogue, while Ubisoft Toronto contributed to other Ubisoft projects. Those related studios can make the development credit easy to mix up.