Eutyches was an archimandrite and heretic who lived in the fifth century at a monastery near Constantinople. A staunch foe of Nestorianism he took an extreme view in the opposite direction, to a form of monophysitism called Eutychianism, during the Christological controversies of the fifth century. His nonnegotiable position ended in his being anathematize by both the Chalcedonian and non-Chalcedonian sides of the controversy.
Little is known of the early life of Eutyches. He is believed to have been born about year 380 and was an archimandrite at a monastery near Constantinople. His name first appeared in 428 as one of the first of those who started the process of complaints against Nestorius‘s teaching. In 431, he attended the Council of Ephesus at which he was in vehement opposition to the teachings of Nestorius of Constantinople. Nestorius asserted an explanation of the natures of Christ such that the Virgin Mary could not be referred to as the “Mother of God” (i.e., Theotokos), Eutyches declared the Christ was “a fusion of human and divine elements.”
The issue at the time was how does one account for the divine and human aspects of Christ. After the condemnation of Nestorianism at the Council of Ephesus, lingering disagreements between the Churches of Alexandria and Antioch were further refined by the protagonists of the two Churches. The Alexandrian doctrine was presented by Cyril of Alexandria, while the Antiochian position was held by Theodoret of Cyrus and John of Antioch both who had accepted the decisions of the Council of Ephesus. While the theologians Cyril and Theodoret came to a reconciliation of their differences as recorded by Cyril in his twelve chapters and other letters, the line of agreement was fine, and their partisans were not convinced. Into this tense arena of both religious and secular feelings, Eutyches took an extreme monophysite position, influenced by Emperor Theodosius II’s minister Chrysaphius, that affected future Orthodox unity even though both sides contended that they both followed the faith of Cyril.
In the confusion after Cyril’s death in 444, Eutyches, not a learned man but much respected, began to denounce the supposed revival of Nestorianism by raising the issue with Pope Leo I, who responded sympathetically. Eutyches criticisms, however, reverted to claims of Apollinarianism that Cyril himself would have rejected. At a patriarchal council at Constantinople in 448, Flavian of Constantinople censured Eutyches for having an unbalanced theology and insisted that Eutyches voice the christological formula of “one person subsisting in two natures.” This Eutyches refused, pressing a position that stressed one nature after incarnation. With this the christological storm was renewed.
As Emperor Theodosius supported Eutyches, Eutyches’ appeal to Theodosius of Flavian's finding against him resulted in a called for a full synodal review. The second council of Ephesus was convened in 449. Presided over by Dioscorus of Alexandria and supported by the emperor, the council became a trial of Flavian, Theodoret, and Ibas of Edessa, who were deposed along with Domnus of Antioch and Eusebius of Dorylaeum, Eutyches was restored to his office. Pope Leo's tome that followed Cyril's faith was discarded by Dioscorus without any consideration. Upon hearing of the actions of the council, Leo called the council ‘a den of thieves’ and is recorded in history as a Robber Council.
While the council was endorsed by Emperor Theodosius, his death on July 28, 450 brought a reversal in Constantinople as Augusta Pulcheria, who had supported Cyril, returned to power. She and her new husband, the General and new emperor Marcian, convened an international council on October 8, 451 at Chalcedon that declared the “robber council” of 449 null and void and, found that Leo's position as expressed in his tome was consistent with Cyril's faith. The council agreed on the orthodoxy of the christology of Cyril's confession.
Eutyches was deposed and exiled, but apparently in exile he continued to expound his position, as attested to by Pope Leo's request in 454 that Eutyches be banished to a more distant place. Eutyches died in exile in 456.