1. Introduction
Almost from its first days, and certainly from the conversion of Emperor Constantine in AD 312, the Christian church was governed by laws of its own making.2 Called canons, these laws quickly became a recognized part of the institutional life of the church.
Early ecumenical councils, like that of Nicaea (325) or Chalcedon (451), enacted canons that affected many aspects of church government, religious practice, and moral conduct - even to the point of attempting to settle a controversy over whether worshippers should kneel or stand while praying.That said, it is equally true and significant that the world in which the Christian church grew was one governed by Roman law. When the church fathers spoke of the law, they normally meant the Roman law. This was a natural and indeed an all but inevitable way for them to speak and think, for they knew no other source of temporal government. They lived in a Roman Empire. They were subject to its law. That fact of life did not mean, of course, that they took the imperial law as possessing sovereign authority over them or the church. Jesus had said that his kingdom was not of this world; ultimate authority belonged to God. His commands were revealed in the Christian Gospel. In fact, the Roman law had played a substantial part in the persecution of the earliest Christians. For them, Roman law therefore stood under the judgement of God. Whatever its hold on human life, religious principle required a certain distance between it and governance of the church itself.
What the exact relationship between the civil law and the law of the church would be in the world was therefore uncertain. No decree fixed it. Some early steps were taken towards the creation of a separate system of ecclesiastical law, but they were hesitant steps, and it cannot be said that a true system of canon law came into existence before the twelfth century.
In the first millennium of the church’s existence, the promulgation of most canons was local and occasional. Their authority was unclear, their invocation in practice infrequent, and their coverage of human life incomplete. No system of regular diocesan courts, much less anything like the Roman Rota, existed to enforce the canons that did exist. Only with arrival of the movement for reform of the church led by the papacy and the revival of learning that led to the foundation of universities in the twelfth century and beyond was the Latin church’s law set on a more ambitious course. The history of the canon law in the East was different in timing and substance. There are parallels, but among other diface=Arial>fferences the ties between imperial law and canon law were closer in the East.3 Although that subject is of intrinsic interest, this volume and this chapter concentrate on the law of the West.A signal event in the movement forwards in the Latin church was the compilation by Gratian of the Concordia discordantium canonum (ca. 1140), the church’s first true law book. Gratian’s method was to assemble a collection of apparently contradictory canons from earlier collections, finding ways to resolve the inconsistencies in them and thereby arrive at a true set of laws for the church. It was a schoolbook, but it also permitted a working out of some practical legal principles. By them, church and clergy could be governed in the world. The Decretum, as it was called, was followed a century later by the promulgation of the Liber extra, a collection of papal decretals commissioned by Pope Gregory IX and edited for clarity and consistency by St Raymond of Penafort. This collection of Decretals built upon the Decretum, not diverging from it on most points, but enlarging it and filling gaps in the coverage of the earlier work. The same pattern was followed by the later collections of papal decretals that were joined together to constitute the Corpus iuris canonici - primarily the Libersextus (1298) and the Clementines (1317). When this work had been accomplished, the body of canon law was complete, and this Corpus remained the basic law of the Catholic church until the twentieth century. Taken all together, the texts in these books were called the ius novum. What came later was called the ius novissimum. Its importance in the history of Western law is shown not only by its longevity, but also by its ubiquity. In the course of time it exercised a strong influence on the laws received in Protestant churches.