In the history of Christianity, "Pentarchy" (from the Greek , Pentarchia from πέντε pente, "five", and ἄρχω archo, "to rule") refers to both a proposed and historical organisational structure where Christendom is administrated by the heads (or Patriarchs) of the five major episcopal sees of the Roman Empire: Rome, Constantinople, Alexandria, Antioch, and Jerusalem. The idea came about because of the political and ecclesiastical prominence of these five sees, but the concept of their universal and exclusive authority was firmly tied to the administrative structure of the Roman Empire. The pentarchy was first tangibly expressed in the laws of Emperor Justinian I (527–565), particularly in Novella 131. The Quinisext Council of 692 gave it formal recognition and ranked the sees in order of preeminence. Especially following Quinisext, the pentarchy was at least philosophically accepted in Eastern Christianity, but generally not in the West, which rejected the Council, and the concept of the Pentarchy. Eventually, the west would come to adopt the doctrine of Papal supremacy as an alternative concept, but this idea would not fully emerge until the eleventh century.