EUTYCHES (c. 378–454), was the archimandrite and founder of the monophysite heresy. Eutyches was born in Constantinople and was archimandrite of a monastery near there. As sponsor of the eunuch Chrysaphius, Eutyches was very influential in the imperial court. Chrysaphius was one of the more powerful counselors of the emperor Theodosius II.

Eutyches was the originator of an extreme form of monophysitism that came to be called Eutychianism. In reaction to the separationist Christology of Nestorius (who accepted two distinct natures in Christ), Eutyches concluded that there was in Christ a single nature. When Theodoret of Cyrrhus wrote the Eranistes against Eutyches' opinions, Flavian, the patriarch of Constantinople (446–449), sent Eutyches to the Council of Constantinople (448) for judgment.

Eutyches appeared at the council but refused to accept the existence of two natures in Christ and was on that account condemned and deposed. Flavian's successor on the throne of Constantinople, Cyril...