Eutyches

Eutyches (Ancient Greek: Εὐτυχής; c. 375–454) or Eutyches of Constantinople was a presbyter and archimandrite at Constantinople. He first came to notice in 431 at the First Council of Ephesus, for his vehement opposition to the teachings of Nestorius. Eutyches was condemned for having adopted a polar opposite view of Nestorianism, where the two natures (Greek: hypostases) of Christ fuse together to form one, single Divine nature, dubbed Monophysitism. This was condemned at the Council of Chalcedon and Third Council of Ephesus. He himself, however, would reject this interpretation of his thought.

Source: Wikipedia — https://en.wikipedia.org/wiki/Eutyches