The Fifth Ecumenical Council (Constantinople, 553)

The Emperor Justinian I sought to bring the opponents of Chalcedon back into unity. To them the Council of 451 seemed to have vindicated Nestorianism, since it had not condemned certain theologians of the Antiochene school. Justinian pressed for the condemnation of the so-called Three Chapters.

These were the person and writings of Theodore of Mopsuestia, the writings of Theodoret of Cyrrhus against St Cyril, and the letter of Ibas of Edessa to Mari the Persian. The Council of Constantinople in 553 condemned them, stressing the unity of Christ's person and that Chalcedon must be read in harmony with St Cyril.

Pope Vigilius of Rome, then in Constantinople, at first refused to take part and resisted the condemnation, but later accepted the Council's decisions in writing.

The condemnation of Origenist teachings (such as the pre-existence of souls) is associated with this time. Whether the relevant anathemas were adopted by the Council itself or by a separate meeting just before it remains debated by historians.

Reconciliation with the non-Chalcedonians did not follow, but Orthodox Christology received a clearer interpretation.