ABSTRACT
Two major sources of jurisprudence and norms shaped European legal systems: Roman law as it was organized in the sixth century under the Eastern Roman emperor Justinian, and the religious law of the Roman Catholic Church that evolved from the time of the first Christian Roman Emperor Constantine to the seventeenth century. Both were important sources of Christian religious law. The reason why an ancient, dead legal system and a system of religious law became important for shaping European jurisprudence is both institutional and the result of a unique series of unforeseeable developments. Forgotten, abbreviated, neglected, and scattered in various pieces, Justinian’s codification of Roman law (529–534) attracted the attention of a shadowy group of men who reassembled it in Italy at the end of the eleventh and the beginning of the twelfth century. The improbability of this rebirth was underlined a century ago by a legal historian who called it a ghost story (Vinogradoff, 1909: 4). A few decades later in the twelfth century, a man named Gratian joined the teachers of Roman law in Bologna and began introducing students to the Church’s law with a revolutionary textbook that he called the Concordia discordantium canonum, the Concord of discordant canons. The jurists shortened his unwieldly title to the Decretum.
