The Second Council of Constantinople is the fifth of the first seven ecumenical councils recognized by both the Eastern Orthodox Church and the Catholic Church. It is also recognized by the Old Catholics and others. Protestant opinions and recognition of it are varied. Some Protestants, such as Calvinists, recognize the first four councils, whereas Lutherans and most Anglo-Catholics accept all seven. Constantinople II was convoked by the Byzantine Emperor Justinian I under the presidency of Patriarch Eutychius of Constantinople. It was held from 5 May to 2 June 553. Participants were overwhelmingly Eastern bishops—only sixteen Western bishops were present, including nine from Illyricum and seven from Africa, but none from Italy—out of the 152 total.

Cyril of Alexandria was the Patriarch of Alexandria from 412 to 444. He was enthroned when the city was at the height of its influence and power within the Roman Empire. Cyril wrote extensively and was a major player in the Christological controversies of the late-4th and 5th centuries. He was a central figure in the Council of Ephesus in 431, which led to the deposition of Nestorius as Patriarch of Constantinople. Cyril is counted among the Church Fathers and also as a Doctor of the Church, and his reputation within the Christian world has resulted in his titles Pillar of Faith and Seal of all the Fathers. The Nestorian bishops at their synod at the Council of Ephesus declared him a heretic, labelling him as a "monster, born and educated for the destruction of the church."