Second Council of Constantinople

The Second Council of Constantinople is the fifth of the first seven ecumenical councils recognized as such by both West and East. Orthodox, Catholics, and Old Catholics unanimously recognize it. Protestant opinions and recognition of it are varied. Traditional Protestants such as Reformed and Lutheran recognize the first four councils, whereas most High Church Anglicans accept all seven. Constantinople II was convoked by Byzantine Emperor Justinian I under the presidency of Patriarch Eutychius of Constantinople and was held from 5 May to 2 June 553. Participants were overwhelmingly Eastern bishops; sixteen Western bishops were present (including those from Illyricum).

The main work of the council was to confirm the condemnation issued by edict in 551 by the Emperor Justinian against the Three Chapters (cf. Three Chapters controversy and Three Chapters schism). The "Three Chapters" were, one, both the person and writings of Theodore of Mopsuestia (d. 428), two, the attacks on Cyril of Alexandria and the First Council of Ephesus written by Theodoret of Cyrrhus (d. c. 466), and three, the attacks on Cyril and Ephesus by Ibas of Edessa (d. 457).

The purpose of the condemnation was to make plain that the Imperial, Chalcedonian (that is, recognizing the hypostatic union of Christ as two natures, one divine and one human, united in one person with neither confusion nor division) Church was firmly opposed to all those who had either inspired or assisted Nestorius, the eponymous heresiarch of Nestorianism—the proposition that the Christ and Jesus were two separate persons loosely conjoined, somewhat akin to adoptionism, and that the Virgin Mary could not be called the Mother of God (Gk. theotokos) but only the mother of Christ (Gk. Christotokos)—which was condemned at the earlier ecumenical council of Ephesus in 431.

Justinian hoped that this would contribute to a reunion between the Chalcedonians and monophysites in the eastern provinces of the Empire; various attempts at reconciliation between the monophysite and orthodox parties were made by many emperors over the four centuries following the Council of Ephesus, none of them succeeding, and some, attempts at reconciliation, such as this—the condemnation of the Three Chapters—causing further schisms and heresies to arise in the process, such as the aforementioned schism of the Three Chapters, and the heresies of monoenergism and monotheletism—the propositions, respectively, that Christ had only one function, operation, or energy (purposefully formulated in an equivocal and vague manner, and promulgated between 610 and 622 by the Emperor Heraclius under the advisement of Patriarch Sergius I of Constantinople) and that Christ only had one will (promulgated in 638 by the same).