First Seven Ecumenical Councils

In the history of Christianity, the first seven ecumenical councils, from the First Council of Nicaea (325) to the Second Council of Nicaea (787), represented an attempt to reach an orthodox consensus and to establish a unified Christendom as the state church of the Roman Empire. The East-West Schism, formally dated to 1054, was still almost three centuries off from the last of these councils, but already by 787 the major western sees, although still in communion with the state church of the Byzantine Empire, were all outside the empire, and the Pope was to crown Charlemagne as emperor 13 years later.

Eastern Orthodox, Roman Catholic, and Anglican churches all claim to trace their clergy by apostolic succession back to this period and beyond, to the earlier period referred to as Early Christianity. However, breaks of unity that still persist today had occurred even during this period.

The Church of the East accepted the first two of these seven councils, but rejected the third, the First Council of Ephesus (431). The Quinisext Council (692), which attempted to establish the Pentarchy and which is not generally considered one of the first seven ecumenical councils, is not accepted by the Roman Catholic Church, which also considers that there have been many more ecumenical councils after the first seven, see Roman Catholic Ecumenical councils 8-21.

This era begins with the First Council of Nicaea, which enunciated the Nicene Creed that in its original form and as modified by the First Council of Constantinople of 381 was seen as the touchstone of orthodoxy on the doctrine of the Trinity. At this point, though the emperors had already ceased to reside habitually at Rome, the church in that city was seen as the first church among churches In 330 Constantine built his "New Rome", which became known as Constantinople, in the East. All of the seven councils were held in the East, specifically in Anatolia and the neighboring city of Constantinople.

The first scholar to consider this time period as a whole was Philip Schaff, who wrote The Seven Ecumenical Councils of the Undivided Church, first published after his death in 1901. The topic is of particular interest to proponents of Paleo-orthodoxy who seek to recover the church before the schisms.