London ? The surviving pages of the world’s oldest Christian Bible have been reunited — digitally.

The early work known as the Codex Sinaiticus has been housed in four separate locations across the world for more than 150 years. But starting Monday, it became available for perusal on the Web at codexsinaiticus.org so scholars and other readers can get a closer look at what the British Library calls a “unique treasure.”

As it survives today, Codex Sinaiticus has just over 400 large leaves of prepared animal skin, each of which measures 15 inches by 13.5 inches. It is the oldest book that contains a complete New Testament and is only missing parts of the Old Testament and the Apocrypha.