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.
if you have all the codex pages decoded and placed on the wall.
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*
The next 40k codex in line is the Blood Angels codex.
1. Red Dragon Codex 2. Bronze Dragon Codex 3. Black Dragon Codex 4. Brass Dragon Codex 5. Green Dragon Codex 6. Silver Dragon Codex 7. White Dragon Codex 8. Gold Dragon Codex 9. Blue Dragon Codex 10. Copper Dragon Codex (2011)
The Codex was created in 2005.
The Codex was invented in the "Ancient Times"
They are part of the Daemonhunters Codex.
Washington Decoded was created in 2007.
Mozart Decoded was created in 2008.
Decoded Feedback was created in 1993.
Codex Pictures was created in 2008.
Codex Astensis was created in 1379.