Council
Ephesus
431 · Ephesus
Attested. The double opening and the 433 formula are well documented. Both sides accused the other of unfair procedure, with reason on both sides.
Convened by. Theodosius II
Issues. Whether Nestorius's reluctance to call Mary Theotokos ('God-bearer') divided Christ, and who controlled the council's opening.
Outcomes. Cyril opened before the Antiochene bishops arrived and had Nestorius deposed. John of Antioch then held a counter-session and deposed Cyril. The emperor first tried to depose both. Reunion in 433 accepted Theotokos and a formula of union, while Nestorius remained deposed. The council is counted as the third ecumenical council by churches that receive it; the Church of the East does not.
Canons or creeds. No new biblical canon. The fight was Christological and procedural.