Monophysitism was a controversial issue in the Eastern Church causing lasting divisions. Included in this controversy are not just religious factors, but political ones also.
The fourth ecumenical council, at Chalcedon* (451), was called into session in order to pacify the spirit of conflict which arose in regard to the nature and person of. Pope Leo of Rome had written his Dogmatic Tome for the Ephesus meeting held two years prior to the Chalcedon Council. Since the Ephesus conference turned out to be such a disgrace, often referred to as the Council of Robbers (see Ephesus, of), the Chalcedon session condemned the action in Ephesus and accepted Pope Leo's document as the rule of faith. The council went on to approve and to present the famous text of the dogma of Chalcedon.
This text issued at Chalcedon presented both sides of the Incarnation clearly, without getting involved in a philosophical explanation as to how the two natures of Christ are united. They proclaimed him “truly God and truly man.” At the same time the council was careful to point out that part of the uniqueness of Christ was that He was one in person and substance, not divided into two persons.
Unfortunately, unity did not proceed from the. Instead of ending the controversy, it was but the beginning of a dispute which would have an immediate effect on the Christian church over the next two centuries as well as a lasting effect. The opposition to the two natures of Christ became known as “Monophysitism.” The name comes from the two Greek words monos (“only”) and fusis (“nature”). The main emphasis of this movement was that there is but one nature in the Incarnation and not two. This, they felt, was the only way to protect the teaching of the unity of Christ's person. To ascribe two natures to Christ was a denial that man could gain ultimate oneness with God which was the goal of salvation. The result of this emphasis is to play down the manhood of Christ and relegate it to the realm of unimportance.
This reaction to orthodoxy which seems to suddenly emerge after Chalcedon in reality goes back to previous aspects of Christian history. Part of its roots can be traced to Christian monasticism as practiced in the Syro-Palestinian region and in Egypt. The monks were in constant battle against their own human weakness and sinfulness. To overcome one's humanity was to gain Christian victory. That which was identified as human had to be destroyed within one's character. For Christ to have a similar human nature as their own would be unthinkable to the Eastern monk.
Monophysitism was also a reaction to Nestorianism.* Nestorius, who became patriarch of Constantinople in 428, was opposed to the expression applied to Mary as “the mother of God.” Mary, he felt, was the mother of Christ, but not the mother of the eternal Logos.* Nestorianism took the views of its founder a bit further than he intended. It pressed the distinction of the two natures of Christ to the extent of a double personality. Jesus was not the God-man, but instead, the God-bearing man. This led to a definite duality in the person of Christ.
Monophysitism was extremely popular among the laity of the Eastern churches. This mob popularity often found expression in many outbursts of violence such as in Alexandria, Antioch, and other church centers in the Middle East. Even to this day this issue on the nature of Christ is one of the main theological divisions between several of the Eastern churches.
See W.H.C. Frend, The Rise of the Monophysite Movement (1972).