The Second Ecumenical Council (Constantinople, 381)

After Nicaea the disputes continued: some bishops rejected the consubstantiality of the Son, and a party known as the Pneumatomachians (Macedonians) denied the divinity of the Holy Spirit. The Emperor Theodosius I, who upheld the Nicene confession, convened a council in Constantinople in 381.

About 150 bishops met under the presidency of St Meletius of Antioch; after his death during the Council St Gregory the Theologian presided, and after Gregory resigned his see, Nectarius of Constantinople.

The Council confirmed the Nicene confession and the teaching on the Holy Spirit, “the Lord, the Giver of Life, who proceeds from the Father, who with the Father and the Son is worshipped and glorified”. The Niceno-Constantinopolitan Creed, read at every Liturgy, is known from the acts of the Council of Chalcedon (451) as the creed of the 150 fathers. Apollinarius, who taught that Christ's human nature was incomplete, was condemned. The Council's third canon gave the bishop of Constantinople primacy of honour after the bishop of Rome, “because it is New Rome”.

The Council concluded the Trinitarian controversies of the 4th century; the teaching on the Trinity formulated by the Cappadocian Fathers — St Basil the Great, St Gregory the Theologian and St Gregory of Nyssa — became the teaching of the whole Church.