Orthodoxy

The Orthodox churches are self-governing, each ruled by its bishops in synod. Unlike the pope, the Ecumenical Patriarch of Constantinople has no authority over the others. They hold to the decrees of the seven ecumenical councils and the teaching of the Church Fathers, and parted from Rome in the schism of 1054. Mysticism was strong among the monks of Mount Athos, whose practice of hesychasm was defended by Gregory Palamas.

In 1337 Orthodoxy was the faith of Byzantium, Serbia, Bulgaria, Georgia, Wallachia and the Russian principalities. The union with Rome agreed at the Council of Florence in 1439 was rejected by most clergy and people in Constantinople, and the city fell to the Ottomans in 1453.