The Antiochene school of biblical interpretation, associated with teachers such as Theodore of Mopsuestia, emphasized the full reality and integrity of Christ's human nature against what it saw as an Alexandrian tendency to merge the human and divine natures so closely that Christ's humanity risked being absorbed or overshadowed. Nestorius, Patriarch of Constantinople and a student of this Antiochene tradition, was condemned at the Council of Ephesus in 431 on the charge of dividing Christ into two separate persons, a reading of his preaching that the Church of the East's own later theologians disputed as a distortion.
The Persian church, already administratively distinct from the church inside the Roman Empire because of its position under Sassanid rule, sided with the condemned Antiochene line rather than its Alexandrian opponents, and at the Synod of Seleucia-Ctesiphon in 486 formally affirmed that Christological direction as its own.
The tradition received its lasting technical formulation from Babai the Great, abbot of the monastery on Mount Izla around 600 CE, who taught two qnome, concrete individual natures, divine and human, united in one parsopa, a single manifest person, a formula built to affirm both the full reality of each nature and the genuine unity of Christ's person without collapsing either the Alexandrian or the Antiochene concern.