Altaïr Ibn-La'Ahad's Codex

"All right, let's see it....ah ha! You found another one."

- Leonardo da Vinci

The Codex was a thirty-page personal journal written by Altaïr Ibn-La'Ahad following the death of Al Mualim, that documents his explorations into the Piece of Eden he possesses as well as offering an auto-biographical view of his life and depicting various assassination-related articles. The Codex found its way to the palace of Genghis Khan, from where it was retrieved by Marco Polo and in turn handed to Dante Alighieri after which the Codex would remain in the Order of Assassins' hands until Domenico Auditore deliberately broke apart and scattered its pages whilst on a ship in Otranto harbour to prevent its capture by drunken pirates hired by the Templars.

The Assassins then attempted to bring the pages of the Codex together, but by 1476 were successful in locating just six pages. In this year however, Ezio Auditore da Firenze took up his father's duty as an Assassin and, by 1499, had succeeded in locating and bringing together all thirty pages scattered across Italy. Each page was encrypted, and the only persons capable of deciphering it were Ezio's father Giovanni Auditore, and Ezio's friend the artist and inventor, Leonardo Da Vinci.

The Codex also held a prediction of the arrival of a "prophet" who would bring together two Pieces of Eden and open the Vault.

Gameplay
Ezio gains 1 health bar per 4 Codex pages he collects (and decrypts). He is also able to upgrade his Hidden Blade with certain gadgets, like the ability to guard using the Hidden Blade, the Poison Blade, the Pistol and a second Hidden Blade, when he recovers some key pages of the Codex.

The Codex Pages are also used using the interconnectivity feature of Assassin's Creed: Bloodlines and Assassin's Creed II in the Playstation 3 version. The more Codex pages Ezio collects, the more synchronization Altaïr gains in Bloodlines. Also, when Ezio collects some key Codex pages to upgrade his Hidden Blade, Altaïr also roughly gains the same upgrade.