Codex Sinaiticus is one of the world's most remarkable books. Written in Greek in the fourth century, it is the oldest surviving complete New Testament, and one of the two oldest manuscripts of the whole Bible. It also stands out as a complex and beautiful artefact. It is one of the most important texts for studying ancient Greek translations of the Hebrew Bible , and for the study of the New Testament and the two other early Christian writings it contains, the Epistle of Barnabas and the Shepherd of Hermas . For many centuries, it was preserved in St Catherine's Monastery on Mount Sinai. New pages were found in the monastery in 1975. Since 2002, a major international project has been creating an electronic version of the manuscript. This book tells the story of the manuscript: the world in which it was made, how it was made, and its later history, including the story of Constantine Tischendorf's visits to the monastery in the nineteenth century, how parts of the manuscript found their way to Leipzig, St Petersburg and the British Library, and the international partnership which created the electronic version.