Non-Chalcedonian Christianity
The Non-Chalcedonian Christianity or Anti-Chalcedonian Orthodox Churches comprises the churches and denominations of Christianity that profess Monophysitism (the theology that Jesus Christ's humanity and divinity was united in one nature) and refuse to accept and upheld the Chalcedonian Definition, which was created at the Council of Chalcedon, the council following Ephesus, in 451 AD.
In contrast to Anti-Chalcedonians, Chalcedonian Christianity professes Dyophysitism (the theology that Jesus' humanity and divinty was inseparable). Anti-Chalcedonians reject Chalcedon for varying reasons, and thus stand in contrast to Chalcedonian Christianity. Today, those who belong to the Oriental Orthodox Ethiopian Orthodox Tewahedo Church and the Coptic Church comprises most people belonging to the Anti-Chalcedonian Orthodox Churches.
It is disputed whether the Nestorian Church is Chalcedonian or not, because while the Nestorian Church refused to accept the Council of Ephesus in 431 AD, and split and broke off their communion with Rome, it is disputed whether they later became Chalcedonian or not, and sources differ on whether they accepted or refused the dyophisitc Chalcedonian Definition.