A gospel harmony composed c. 172 C.E., the Diatessaron is one of the earliest witnesses to the gospels. Regarded as the first version of the gospels in Latin, Syriac, and Armenian, the Diatessaron was used by Encratites, Judaic-Christians, and "Great Church" Christians alike. This study is the first comprehensive treatment of the Diatessaron in more than a century. After sketching the second-century setting and Tatian's biography, it describes virtually every Diatessaronic witness and provides a scholar-by-scholar summary of research from 546 to the present....