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.

Canon law touched nearly every aspect of medieval society, including many issues we now think of as purely secular. It regulated marriages, oaths, usury, sorcery, heresy, university life, penance, just war, court procedure, and Christian relations with religious minorities. Canon law also regulated the clergy and the Church, one of the most important institutions in the Middle Ages. This Cambridge History offers a comprehensive survey of canon law, both chronologically and thematically. Written by an international team of scholars, it explores, in non-technical language, how it operated in the daily life of people and in the great political events of the time. The volume demonstrates that medieval canon law holds a unique position in the legal history of Europe. Indeed, the influence of medieval canon law, which was at the forefront of introducing and defining concepts such as 'equity,' 'rationality,' 'office,' and 'positive law,' has been enormous, long-lasting, and remarkably diverse.

This study of Burchard's 'Decretum', a popular book of Catholic canon law compiled just after the year 1000, sheds new light on the development of law and theology long before the Gregorian Reform, normally considered as a watershed in the history of the Latin Church. Practical episcopal concerns and an appreciation of new scholarly methods led Burchard to be dissatisfied with the quality of contemporary jurisprudence and particularly with the teaching texts available to local bishops. Drawing upon new manuscript discoveries, the author shows how Burchard tried to create a new text that would address these problems. He carefully selected and compiled canons from earlier collections and then went on to tamper systematically with the texts he had chosen. By doing so, he created a book of church law that appeared to be based on indisputable authority, that was internally consistent and that was easy to apply through logical extrapolation to new cases. The present study thus provides a window into the development of legal and theological reasoning in the medieval West, and suggests that, thanks to the work of ambitious bishops, the flowering of law and theology began far earlier, and for different reasons, than scholars have heretofore supposed.