Council of Ephesus

The ecumenical council held at Ephesus in 431 affirmed Mary as Theotokos and condemned Nestorius’s teaching about Christ.

Theotokos: A Greek title meaning “God-bearer,” affirmed for Mary at the Council of Ephesus. The council’s affirmation of this title expressed its claim that Christ is one person, truly divine.
First Council of Nicaea: The 325 ecumenical council that rejected Arianism and defined the Son as consubstantial with the Father. Its definition of Christ’s divinity formed a foundation for the later dispute at Ephesus.
Council of Chalcedon: The 451 ecumenical council that defined Christ as one person in two natures, divine and human. It addressed Christological tensions that the Council of Ephesus had not resolved.
Council of Ephesus (431) sessions: The meetings and decisions of the 431 council, including its opening before John of Antioch arrived. The rival sessions explain why the council’s legitimacy and conduct became contentious.
Nestorianism: A label for teachings seen as dividing Christ’s divine and human identities; its application to Nestorius remains disputed. The council condemned Nestorius’s teaching over whether Christ’s unity permitted calling Mary Theotokos.
Council of Constantinople (381): The 381 ecumenical council that reaffirmed Nicaea and expanded the creed’s teaching on the Holy Spirit. Its creed supplied the shared doctrinal background for the council’s Christological debate.
Church of the East: A Christian tradition that developed chiefly in the Sasanian Empire and became institutionally distinct from the Roman church. Later histories linked its separation to the condemnation of Nestorius, though that connection oversimplifies its origins.
Memnon of Ephesus: The bishop of Ephesus who supported Cyril’s party during the 431 council. His role in the opening proceedings connected local authority to the council’s factional conflict.
Cyril of Alexandria: The bishop of Alexandria who led the opposition to Nestorius at the Council of Ephesus. Cyril’s arguments and letters set the council’s theological direction.
Apollinarianism: A fourth-century teaching that Christ’s divine nature replaced his human rational mind. Earlier disputes over Christ’s humanity shaped the terms used at Ephesus.

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