Pentarchy

The Pentarchy (from penta, five, and arche, rule) is the system of five ancient patriarchates recognized by the Ecumenical Councils as governing the universal Church: Rome (first in honor), Constantinople (second), Alexandria (third), Antioch (fourth), Jerusalem (fifth). The system was never fully implemented in practice (since Rome's separation) but remains the theoretical basis of Orthodox ecclesiology's understanding of universal church order. The ranking is based on political significance (capitals and apostolic importance) rather than jurisdictional subordination.