The Council of Ephesus was convened in 431 by Theodosius II, emperor of the eastern half of the Roman Empire, and he did so at the request of Nestorius. Nestorius’ teaching about the nature of Christ was generating a great deal of controversy in the church, and he requested a council in the hopes of being able to prove his orthodoxy and silence his detractors. While Theodosius did not attend, he sent the head of his imperial palace guard, Count Candidian, to represent him. The council met in Ephesus, near present day Selcuk in Turkey with between 200 and 250 bishops in attendance.
Though he would not actually be present, the dominant personality at the Council of Ephesus was Nestorius who was originally from Antioch in Syria. Nestorious was a gifted speaker who had been appointed by Theodosius II as Archbishop of Constantinople. The second major character was Cyril, Archbishop of Alexandria. The two men would represent the two sides in a conflict with profound implications to the Christian faith.
The Council of Ephesus confirmed the Nicene Creed and the title Theotokos for Mary as a legitimate title based on that creed. They also condemned Nestorianism and excommunicated all those bishops who did not hold to the council’s decision.