Tixeront, author of a well known patrology (French, then translated into English), in this volume studies the origins of Christianity in Edessa. The initial chapters cover the question from both a historical and a legendary perspective, and then Tixeront turns specifically to an analysis of the so-called Doctrine of Addai. He examines the origin, historical value, and significance of the legend. An appendix is focused on “the invention of the true Cross” and the Protonice legend, which are closely associated with Christianity in Edessa. The book concludes with three texts of the correspondence between Jesus and Edessa’s King Abgar, first in Greek, from a papyrus of El-Fayyum, then a previously unedited Syriac text from a Paris manuscript, and finally a previously unedited Arabic text from a Vatican manuscript, which is also here translated into French. Every reader interested in early Syriac Christianity and Syriac literature will welcome the reappearance of this study.