When you decode the codex pages, you will find that it makes a map fo the world, however... there is an X on Rome, you then have to talk to a few people then travel to rome to face the pope and get back the apple of Eden... after that some weird stuff happens *I won't spoil it for you*
if you have all the codex pages decoded and placed on the wall.
Take them to the codex wall in the Villa, and place them there. Then view them in Eagle Vision and rotate them until the World Map lines up. Once you get to the final memory sequence this will allow you to complete the game.
The Codex - novel - has 416 pages.
Codex - novel - has 376 pages.
The Rivan Codex has 480 pages.
Codex Seraphinianus contains around 360-370 pages, depending on the edition.
The next 40k codex in line is the Blood Angels codex.
All the codex pages match up to a world map, shouldn't be so hard to find that shape...
By stating that the codex pages are already unlocked, I'm assuming you need to know how to use them on the codex wall in the Villa. Just interact with the codex wall and turn on your eagle vision to see a scrambled image. Use the button which corresponds to the rotation of each page to assemble a world map. You can do this with any amount of pages you've found, but all 30 pages must be done when the congregation of assassins meed in the codex room much later in the game before leaving for Rome and the final stage. Now, finding those codex pages... you will see them in the town on your map if you purchased a treasure map for it and the rest will be awarded to you after completing certain missions. Good luck. ShaqueNova.
In Assassin's Creed 2, there is no official cheat code to instantly obtain all codex pages. The codex pages must be located throughout the game world by exploring and completing various missions. Players can use online guides or walkthroughs to help locate all the codex pages more efficiently. It is important to note that using cheats or hacks to obtain items in the game may violate the game's terms of service and could result in penalties.
16 pages!!! i think always collect imperial guard collection though!!=]
SPOILER ALERT!!!! The codex pages ultimately form a hidden map of the Earth.