Chalcedonianism

Chalcedonian Christianity is a term referring to Christian denominations adhering to the Definition of Chalcedon (AD 451), a religious doctrine concerning the divine and human natures of Jesus Christ. While most extant Christian communions and confessions are understood to be Chalcedonian, from the 5th to the 8th centuries the ascendancy of Chalcedonian Christology was not always certain.

The dogmatical disputes raised during the Council of Chalcedon led to the Chalcedonian Schism thus to the formation of the Non-Chalcedonian body of churches known as Oriental Orthodox. The Chalcedonian churches remained united with the Holy See of Rome, the Ecumenical Patriarchate of Constantinople (or "New Rome") and the Eastern Orthodox patriarchates of the Middle East (namely Alexandria, Antioch and Jerusalem). Together, these metropolitan archbishoprics were ranked in honor as the pillars of Catholic Christendom and of a Chalcedonian confession of faith, superseding the early de facto leadership of three Petrine sees (in order of primacy: Rome, Alexandria, and Antioch). During the 6th-century reign of Emperor Justinian I, the five patriarchates were recognised as the Pentarchy, the official ecclesiastical authority of the Imperial Christian Church.