Gregorian Reform
Since the 5th century, Christendom had been divided into a pentarchy of five sees with Rome holding the primacy. This was determined by canonical decision and did not entail hegemony of any one local church or patriarchate over the others. However, Rome began to interpret her primacy in terms of sovereignty, as a God-given right involving universal jurisdiction in the Church. The collegial and conciliar nature of the Church, in effect, was gradually abandoned in favor of a supremacy of unlimited papal power over the entire Church. These ideas were finally given systematic expression in the West during the Gregorian Reform movement of the 11th century.