This book presents a comparative study of church order in the East and West of the Christian world. It deals with the development of canon law from the 6th century, the time of Dionysius Exiguus and John Scholastikos, up to the period of Balsamon and Gratian. While the focus is upon Rome and Constantinople, the author includes in his discussion the churches under Islamic rule, in Syria and Persia, and describes the beginnings of Slavonic canon law in Moravia. The issues of church government, the discipline of the clergy (married or celibate), and the question of divorce and re-marriage are key themes. By illustrating how these were faced in the canon law of the Christian churches of late antiquity and the earlier Middle Ages, the book highlights questions of unity and diversity within the Christian tradition.