Picture: the British Library's Codex Sinaiticus containing the Book of Psalms and the Gospel of Mark. © the British Library

A “unique treasure” of Biblical history is to be made available online for the first time through a collaborative project between the British Library and three other major international institutions.

The Codex Sinaiticus, considered to be the world’s most important Biblical manuscript, dates from the fourth century and is thought to be the earliest, most complete Christian bible.

The manuscript is, however, split up and housed in four different locations - London, Sinai, St Petersburg and Leipzig. This means that pages from one book of the bible manuscript might be housed in two or more different repositories.

The initial website launch on July 24 2008 will mean that 25 per cent of the manuscript’s 800 extant pages and over 40 fragments will be available online. This will be the first time that some pages have been seen together in one place for centuries.

As well as images of the actual pages, the website will have a transcription of the manuscript’s contents along with all corrections added throughout its long history. The site will also include many interactive features, allowing scholars and enthusiasts alike to perform research and access the manuscript’s features.

A detail from the Codex Sinaiticus showing a tear in the ancient parchment. © the British Library

While the project intends to have all parts of the Codex Sinaiticus online by July 2009, this year’s initial launch will give access to 106 pages held by the British Library. These include the complete Book of Psalms and the Gospel of Mark.

A further 28 fragment pages from the British Library collection will also be added. These pages enable the online completion of a further six Biblical texts when joined with the parts of the manuscript housed at Leipzig University. These texts include 1 Chronicles, Jeremiah and Lamentations.

As well as translations of some parts of the manuscript from the Greek into English and German, the website will also allow users to explore cross-referencing between both the transcription and the image of the manuscript itself. For instance, pointing at a word on the transcription will highlight the equivalent word in the image.

A page from the Codex Sinaiticus showing the many corrections and annotations made over the years. © the British Library

Different lighting choices will be available to give users an experience of seeing the manuscript in different ways. Users can choose between standard light for straightforward research or raking light. Raking light, which lights an object from an angle, will allow an aesthetic appreciation of the physical features of the ancient parchment.

The British Library’s Head of Western Manuscripts said: “Only a few people have ever had the opportunity to see more than a couple of pages of the world’s oldest Bible. The website will make it possible for anyone to see this absolutely unique treasure.”

Alongside the university at Leipzig, other holders of the parts of the Codex and collaborators with the British Library in this groundbreaking project include the National Library of Russia and the Greek Orthodox St Catherine’s Monastery in Sinai. This monastery which is the oldest continuously active Christian community, traces its own roots, like that of the Codex Sinaiticus, back to the fourth century.