In Assassin's Creed II, which codex author is revealed to be Altaïr Ibn-La'Ahad?

In Assassin's Creed II, Altaïr Ibn-La'Ahad is revealed as the author of the codex pages.

The codex is a collection of writings and diagrams that Ezio gathers during the Renaissance story. Its pages contain information about the Assassin Order, hidden knowledge, and technological designs. The game eventually identifies Altaïr, the protagonist of the original Assassin's Creed, as the figure behind the codex.

This revelation connects Ezio's fifteenth-century adventure with Altaïr's twelfth-century story. Altaïr's knowledge survives across generations through the Assassin Brotherhood, making the codex an important narrative bridge between the first two games.

Leonardo da Vinci helps Ezio interpret and reproduce some codex designs, but he is not the codex's author. Machiavelli is a Brotherhood ally in the Italian storyline, while Ezio is the character collecting the pages.