First seven ecumenical councils
These seven events represented an attempt by Church leaders to reach an orthodox consensus, restore peace[1] and develop a unified Christendom.
This era begins with the First Council of Nicaea in AD 325, convened by the emperor Constantine I following his victory over Licinius and consolidation of his reign over the Roman Empire.
Only within Eastern Orthodoxy is its authority commonly considered ecumenical; however, the Orthodox do not number it among the seven general councils, but rather count it as a continuation of the fifth and sixth.
The council also addressed the issue of dating Easter (see Quartodecimanism and Easter controversy), recognised the right of the See of Alexandria to jurisdiction outside of its own province (by analogy with the jurisdiction exercised by Rome) and the prerogatives of the churches in Antioch and the other provinces[6] and approved the custom by which Jerusalem was honoured, but without the metropolitan dignity.
Even when Arius died in 336, one year before the death of Constantine, the controversy continued, with various separate groups espousing Arian sympathies in one way or another.
[8] In 359, a double council of Eastern and Western bishops affirmed a formula stating that the Father and the Son were similar in accord with the scriptures, the crowning victory for Arianism.
The Eastern Orthodox Church uses the council's text but with the verbs expressing belief in the singular: Πιστεύω (I believe) instead of Πιστεύομεν (We believe).
After quoting the Nicene Creed in its original form, as at the First Council of Nicaea, without the alterations and additions made at the First Council of Constantinople, it declared it "unlawful for any man to bring forward, or to write, or to compose a different (ἑτέραν) Faith as a rival to that established by the holy Fathers assembled with the Holy Ghost in Nicæa.
"[16] The council repudiated the Eutychian doctrine of monophysitism, described and delineated the "Hypostatic Union" and two natures of Christ, human and divine; adopted the Chalcedonian Definition.
This move was instigated by Emperor Justinian in an effort to conciliate the monophysite Christians, it was opposed in the West, and the Popes' acceptance of the council caused a major schism.
[20] Prior to the Second Council of Constantinople was a prolonged controversy over the treatment of three subjects, all considered sympathetic to Nestorianism, the heresy that there are two separate persons in the Incarnation of Christ.
Eastern Patriarchs supported the Emperor, but in the West his interference was resented, and Pope Vigilius resisted his edict on the grounds that it opposed the Chalcedonian decrees.
[22] The council was not immediately recognized as ecumenical in the West, and Milan and Aquileia even broke off communion with Rome over this issue.
Semi-Autonomous: In the 9th century, Emperor Michael III deposed Patriarch Ignatius of Constantinople and Photius was appointed in his place.
After Michael was murdered, Ignatius was reinstated as patriarch without challenge and in 869–870 a council in Constantinople, considered ecumenical in the West, anathematized Photius.
