After years of painstaking work by experts on several continents, the oldest surviving Christian Bible in the world has been reunited and made available on the Internet.

About 800 pages of the Codex Sinaiticus manuscript -- considered by many to be one of the world's greatest written treasures -- were posted online this week, marking the completion of a massive project.

The pages are held by four separate institutions in Britain, Egypt, Germany and Russia -- and until now scholars or researchers had to travel to the various locations in order to study them.

In July 2008 the first digitized pages were posted online as part of a joint effort by the institutions, and the completed project went live on Monday.

Scot McKendrick, the British Library's Head of Western Manuscripts, said the project represents an important step forward for Biblical scholars.

"The Codex Sinaiticus is one of the world's greatest written treasures," McKendrick said in a news release.

"This 1,600-year-old manuscript offers a window into the development of early Christianity and first-hand evidence of how the text of the bible was transmitted from generation to generation."

The manuscript, written in Greek at the time of Constantine the Great, includes hand-written corrections, serving as evidence of how the text of the Bible was passed down throughout the centuries.

In addition to containing most of the Old Testament, it also boasts the oldest known version of the New Testament.

Written in the fourth century on pages that were bound together, rather than on scrolls, the manuscript may be the oldest book in the world.

It originally contained the entire New and Old Testament as well as the Apocrypha, though half of the Old Testament has since been lost. It also includes writings not included in the current Bible, including an epistle ascribed to the Apostle Barnabas and 'The Shepherd' by Hermas.

The online version of the book includes full transcription of the hand-written text, including the revisions and corrections that were made to the text

"It will also allow researchers into the history of the book as a physical object to examine in detail aspects of its fabric and manufacture: pages can be viewed either with standard light or with raking light which, by illuminating each page at an angle, highlights the physical texture and features of the parchment," states the release.

It is also possible to compare the different handwriting of the four scribes who are believed to have copied the text.

The manuscript has come a long way from its discovery in 1844 in a monastery in Egypt. The book is believed to have lain undiscovered for 1,500 years before it was found.

Upon its discovery, it was split between Egypt, Russia, Germany and Britain -- where the pages remained separate until now.