In Assassin's Creed Revelations, which legendary Assassin does Ezio Auditore seek in Constantinople?

Altaïr Ibn-La'Ahad is the legendary Assassin whom Ezio Auditore seeks in Assassin's Creed Revelations.

Ezio travels to Constantinople to recover keys that unlock the Masyaf fortress library. The keys contain recorded memories of Altaïr, the protagonist of the first Assassin's Creed, so Revelations alternates between Ezio's sixteenth-century missions and Altaïr's earlier life.

Altaïr's memories show his leadership of the Levantine Brotherhood and the later stages of his life. The connection gives Ezio a historical predecessor whose experiences help explain the library and the long legacy of the Assassin Order.

Desmond is the modern-day character whose memories are accessed through the Animus, not the figure Ezio seeks in Constantinople. Al Mualim is Altaïr's former mentor, while Niccolò Polo is associated with the Polo memoirs and the game's historical setting. Revelations was released in 2011.