Eastern Orthodox Church

=== Ecumenical councils ===

{{Main|First seven Ecumenical Councils}}
{{See also|State church of the Roman Empire}}
[[File:Nicaea icon.jpg|thumb|An [[icon]] depicting [[Constantine I|the Emperor Constantine]] and the [[bishop]]s of the First Council of Nicaea (325) holding the [[Niceno-Constantinopolitan Creed|Niceno–Constantinopolitan Creed of 381]]]]

Several doctrinal disputes from the fourth century onwards led to the calling of [[ecumenical council]]s. In the Orthodox Church, an ecumenical council is the supreme authority that can be invoked to resolve contested issues of the faith. As such, these councils have been held to resolve the most important theological matters that came to be disputed within the Christian Church. Many lesser disagreements were resolved through local councils in the areas where they arose, before they grew significant enough to require an ecumenical council.

There are seven councils authoritatively recognised as ecumenical by the Eastern Orthodox Church:
# The [[First Council of Nicaea|First Ecumenical Council]] was convoked by the Roman Emperor Constantine at [[Nicaea]] in 325 and presided over by the Patriarch [[Pope Alexander I of Alexandria|Alexander of Alexandria]], with over 300 bishops condemning the view of [[Arius]] that the Son is a created being inferior to the Father.<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8062|title=The First Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[First Council of Constantinople|Second Ecumenical Council]] was held at Constantinople in 381, presided over by the Patriarchs of Alexandria and Antioch, with 150 bishops, defining the nature of the Holy Spirit against those asserting His inequality with the other persons of the Trinity.<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8065|title=The Second Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[First Council of Ephesus|Third Ecumenical Council]] is that of Ephesus in 431, presided over by the Patriarch of Alexandria, with 250 bishops, which affirmed that Mary is truly "Birthgiver" or "Mother" of God (''[[Theotokos]]''), contrary to the teachings of [[Nestorius]].<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8066|title=The Third Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[Council of Chalcedon|Fourth Ecumenical Council]] is that of Chalcedon in 451, Patriarch of Constantinople presiding, 500 bishops, affirmed that Jesus is truly God and truly man, without mixture of the two natures, contrary to [[Monophysite]] teaching.<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8067|title=The Fourth Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[Second Council of Constantinople|Fifth Ecumenical Council]] is the second of Constantinople in 553, interpreting the decrees of Chalcedon and further explaining the relationship of the two natures of Jesus; it also condemned the alleged teachings of [[Origen]] on the pre-existence of the soul, etc.<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8068|title=The Fifth Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[Third Council of Constantinople|Sixth Ecumenical Council]] is the third of Constantinople in 681; it declared that Christ has two wills of his two natures, human and divine, contrary to the teachings of the [[Monothelites]].<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8069|title=The Sixth Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>
# The [[Second Council of Nicaea|Seventh Ecumenical Council]] was called under the Empress Regent [[Irene of Athens]] in 787, known as the second of Nicaea. It supports the [[veneration]] of [[icon]]s while forbidding their worship. It is often referred to as "The Triumph of Orthodoxy".<ref>{{cite web|url=http://www.goarch.org/ourfaith/ourfaith8071|title=The Seventh Ecumenical Council – Greek Orthodox Archdiocese of America|access-date=5 March 2015}}</ref>

There are also two other councils which are considered ecumenical by some Eastern Orthodox:

* The [[Fourth Council of Constantinople (Eastern Orthodox)|Fourth Council of Constantinople]] was called in 879. It restored [[Photios I of Constantinople|Photius]] to his [[Ecumenical Patriarchate of Constantinople|See in Constantinople]] and condemned any alteration of the Nicene-Constantinopolitan Creed of 381.
* The [[Fifth Council of Constantinople]] was actually a series of councils held between 1341 and 1351. It affirmed the [[Hesychasm|hesychastic]] theology of [[Gregory Palamas]] and condemned the philosopher [[Barlaam of Calabria]].