Any of several church councils, some of which are recognized as ecumenical, held in the city of Constantinople.
The First Council of Constantinople, the second ecumenical council of the Christian church, was summoned by Emperor Theodosius I in 381. It promulgated the Nicene Creed and declared finally the Trinitarian doctrine of the equality of Father, Son, and Holy Spirit . It gave the bishop of Constantinople honour second only to that of the pope . Only Eastern bishops were summoned to the council, but the Greeks claimed that it was ecumenical. It did come to be so regarded, though the Western church did not accept the ranking of Constantinople as second to Rome until the 13th century. The Second Council of Constantinople, held in 553, was called by Justinian I ; by endorsing an edict of Justinian's, it lent support to Monophysitism and diminished the earlier Council of Basil I , resulted in the excommunication of St. {{link=Photius, Saint">Photius and increased the animosity between the Eastern and Western churches.