Nestorius

Mar Nestorius
Nestorius as envisioned by the 17th century dutch printmaker Romeyn de Hooghe, in the book History of the church and heretics
Archbishop of Constantinople
Born	c. 386 Germanicia, Syria (now Kahramanmaraş, Turkey)
Died	c. 450 (aged 63 or 64) Great Oasis of Hibis (al-Khargah), Egypt
Venerated in	Assyrian Church of the East, Syro-Malabar Church, Ancient Church of the East
Feast	October 25
Controversy	Christology, Theotokos

Nestorius (/ˌnɛsˈtɔːriəs/; in Greek: Νεστόριος; c. 386 – 450) was Archbishop of Constantinople (now Istanbul) from 10 April 428 to August 431, when Emperor Theodosius II confirmed his condemnation by the Council of Ephesus on 22 June.

His teachings included a rejection of the long-used title of Theotokos, "Mother of God", for Mary, mother of Jesus, and they were considered by many to imply that he did not believe that Christ was truly God. That brought him into conflict with other prominent churchmen of the time, most notably Cyril of Alexandria, whom he accused of heresy.

Nestorius sought to defend himself at the First Council of Ephesus in 431 but instead found himself formally condemned for heresy by a majority of the bishops and was subsequently removed from his see. On his own request, he retired to his former monastery, in or near Antioch. In 435, Theodosius II sent him into exile in Upper Egypt, where he lived on until 450, strenuously defending his orthodoxy. His last major defender within the Roman Empire, Theodoret of Cyrrhus, finally agreed to anathematize him in 451 during the Council of Chalcedon.

From then on, he had no defenders within the empire, but the Church of the East never accepted his condemnation. That led later to western Christians giving the name Nestorian Church to the Church of the East where his teachings were deemed Orthodox and in line with its own teachings. Nestorius is revered as among three "Greek Teachers" of the Church (in addition to Diodore of Tarsus and Theodore of Mopsuestia). Parts of the Church of the East's Eucharistic Service, which is known to be among the oldest in the world, is contributed to with prayers attributed to Nestorius himself.