Saint Meletius was a Christian bishop of Antioch from 360 until his death in 381. However, his episcopate was dominated by a schism, usually called the Meletian schism.During the reigns of the Homoian (Homoean) emperors Constantius and Valens, he was exiled in 361–362, 365–366 and 371–378, implying his opposition to Homoianism.Meletius was also strongly opposed by a rival pro-Nicene bishop named Paulinus who was faithful to the memory of Eustathius of Antioch. "The fragments of Eustathius that survive present a doctrine that is close to Marcellus. ... Eustathius insists there is only one hypostasis." While Athanasius of Alexandria and bishop Damasus of Rome opposed Meletius and supported Paulinus, Basil of Caesarea supported Meletius.

The First Council of Constantinople was a council of Christian bishops convened in Constantinople in AD 381 by the Roman Emperor Theodosius I. This second ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, except for the Western Church, confirmed the Nicene Creed, expanding the doctrine thereof to produce the Niceno-Constantinopolitan Creed, and dealt with sundry other matters. It met from May to July 381 in the Church of Hagia Irene and was affirmed as ecumenical in 451 at the Council of Chalcedon.