The moment
Emperor Marcian, with the empress Pulcheria, called the council, which declared Christ one person in two natures, following a letter of Pope Leo I, and deposed Dioscorus of Alexandria. The churches of Egypt, Syria and Armenia, today's Oriental Orthodox, rejected the formula. The Church of the East in Persia, which had never accepted Ephesus in 431, stood on the opposite side of the argument.
People: Leo I, Dioscorus of Alexandria, Pulcheria, Marcian