The Ecumenical Councils

Councils are assemblies of clerics belonging to the Church hierarchy and/or theological experts. They discuss and regulate matters of Church doctrine and discipline. The most well-known such assemblies are the so-called "Ecumenical Councils" which gathered bishops from the whole Christian "oikoumene", decrees of which were of great importance to Christendom and were approved by the pope. The term "council", generally, may also apply to Church meetings of lesser importance. In such cases, the meetings are termed another way: "general synod of the East (or the West)" in case the meeting gathered the bishops of the western or eastern Church only; "patriarcal (or national, or primatical) council" when the meeting is about a patriarchate, a nation or the provinces submitted to a primate; a "provincial council" is gathering the suffragan bishops of the metropolitan of one ecclesiastical province, as a "diocesan synod" gathers the clerics of a bishopric see. On a other hand, one can note that the Canon right of the time, though stabilised, was still fragmented by imperfect collections

The following list is summarizing the ecumenical councils which occurred from the early Church to the Carolingian times

The ecumenical councils which occurred from the early Church to the Carolingian times:

• the first council of Nicaea (first ecumenical council, 325). The legate of Pope Sylvester and the emperor Constantine were present. The Creed of Nicaea was defined there, asserting the true divinity of Jesus against the Arian heresy. This council fixed too the date of Easter against the Quartodeciman heretics
• the first council of Constantinople (second ecumenical council, 381). Pope Damasus and emperor Theodosius I were attending. The council was directed against the followers of Macedonius who rejected the divine procession of the Holy Ghost. It added to the Nicene Creed the clauses referring to the Holy Ghost
• the council of Ephesus (third ecumenical council, 431). This council was presided over by St. Cyril of Alexandria, representing Pope Celestine I. The council defined the true personal unity of Christ, declared Mary the Mother of God ("theotokos") against Nestorius, Bishop of Constantinople, and it renewed the condemnation of Pelagius
• the council of Chalcedon (fourth ecumenical council, 451). The council was presided by Pope Leo the Great and the emperor Marcian. It defined the two natures -divine and human of Christ- against Eutyches
• the second council of Constantinople (fifth ecumenical council, 553). The council was presided over by Pope Vigilius and the Byzantine emperor Justinian I. It condemned the errors of Origen and certain writings of Theodoret, of Theodore, bishop of Mopsuestia, and of Ibas, bishop of Edessa. The council, on the other hand, confirmed the first four ecumenical councils, especially that of Chalcedon, which was contested by some heretics
• the third council of Constantinople (sixth ecumenical council, 680-681). It was presided over by Pope Agatho and the Byzantine emperor Constantine Pogonatus. It put an end to the monothelitist heresy. It defined two wills in Christ, the divine and the human, and them being two distinct principles of operation. It anathematized Sergius, Pyrrhus, Paul, Macarius, and all their followers
• the second council of Nicaea (seventh ecumenical council, 787). The second council of Nicaea put a first stop to the crisis of the Iconoclam. It was convoked by Irene, the mother of the Byzantine emperor Constantine VI. The legates of Pope Adrian I presided over the council. The council regulated the veneration of the holy images
• the fourth council of Constantinople (eighth ecumenical council, 869). It was presided over by Pope Adrian II and the Byzantine emperor Basil. 3 papal legates and 4 patriarchs were attending. The council had the Acts of an irregular council brought together by Photius against Pope Nicholas and Ignatius, the legitimate Patriarch of Constantinople, burned. The council condemned Photius who had unlawfully be elevated to the patriarchate of Constantinople

All the following ecumenical (from a Roman Catholic point of view) councils took place in the western Christendom only, as the eastern Church eventually definitively severed any link with the western one in the middle of the 11th century