Which Assassin’s Creed game features the historical figure Leonardo da Vinci as Ezio’s ally?

Assassin’s Creed II features Leonardo da Vinci as Ezio Auditore’s ally.

In the game, Leonardo is portrayed as a gifted inventor and artist who becomes one of Ezio’s most important supporters. He helps decode pages of the Codex, creates equipment based on recovered designs, and provides technical assistance during Ezio’s missions. Their friendship links Renaissance art, engineering, and the game’s fictional ancient technology.

The historical Leonardo da Vinci lived from 1452 to 1519 and was active in Florence, Milan, and other Italian courts. Assassin’s Creed II uses real details from his life while placing him inside a fictional conspiracy involving Assassins and Templars. Leonardo also appears in later Ezio-centered entries, including Brotherhood and Revelations, but Assassin’s Creed II is the game that first establishes his relationship with Ezio. The character should not be confused with the modern-day inventor Shaun Hastings or with the historical figures featured in other series installments.