Constantinople II 553 Fifth Ecumenical Council
We further declare that we hold fast to the decrees of the four Councils, and in every way follow the holy Fathers, Athanasius, Hilary, Basil, Gregory the Theologian, Gregory of Nyssa, Ambrose, Theophilus, John (Chrysostom) of Constantinople, Cyril, Augustine, Proclus, Leo and their writings on the true faith. (Session I: Extracts from the Acts, Letter from the Emperor)