A Christian theologian from the Catechetical School of Antioch, several of his teachings in the fields of Christology and Mariology were seen as controversial and caused major disputes.

It is in virtue of this union that the holy Virgin is called Theotokos Nestorius sought to defend himself at the 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.

Nestorius is revered as among three "Greek Teachers" of the Church of the East (in addition to Diodorus of Tarsus and Theodore of Mopsuestia).

The discovery, translation and publication of his Bazaar of Heracleides at the beginning of the 20th century have led to a reassessment of his theology in Western scholarship.

It is now generally agreed that his ideas were not far from those that eventually emerged as orthodox, but the orthodoxy of his formulation of the doctrine of Christ is still controversial.

Sources place the birth of Nestorius around 386 in the city of Germanicia in the Province of Syria, Roman Empire (now Kahramanmaraş in Turkey).

Nestorius's opponents charged him with detaching Christ's divinity and humanity into two persons existing in one body, thereby denying the reality of the Incarnation.

This naturally caused great excitement at Constantinople, especially among the clergy, who were clearly not well disposed to Nestorius, the stranger from Antioch.

He now hastened it, and the summons had been issued to patriarchs and metropolitans on 19 November, before the pope's sentence, delivered through Cyril of Alexandria, and was served on Nestorius.

[9] Emperor Theodosius II convoked a general church council, at Ephesus, itself a special seat for the veneration of Mary, where the Theotokos formula was popular.

Cyril of Alexandria took charge of the Council of Ephesus in 431, opening debate before the long-overdue contingent of Eastern bishops from Antioch arrived.

The only complete treatise is the lengthy defence of his theological position, The Bazaar of Heraclides, written in exile at the Oasis, which survives in Syriac translation.

[15] In 1895, a 16th-century book manuscript containing a copy of a text written by Nestorius was discovered by American missionaries in the library of the Nestorian patriarch in the mountains at Qudshanis, Hakkari.

In the Bazaar, written about 450, Nestorius denies the heresy for which he was condemned and instead affirms of Christ "the same one is twofold" — an expression that some consider similar to the formulation of the Council of Chalcedon.

Nestorius' earlier surviving writings, however, including his letter written in response to Cyril of Alexandria's charges against him, contain material that has been interpreted by some to imply that at that time he held that Christ had two persons.