First seven ecumenical councils

The First Seven Ecumenical Councils refer to the foundational meetings of Christian bishops convened to discuss and settle matters of Church doctrine, heresy, and practice within the first millennium of Christianity. These councils are recognized as ecumenical, meaning they are considered universally authoritative within Christianity, particularly among the Roman Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox Churches, and some Protestant denominations. The decisions made at these councils had a profound impact on the development of Christian theology and the establishment of the creeds that continue to shape Christian belief and practice.

First Council of Nicaea (325)

The First Council of Nicaea was convened by Emperor Constantine in 325 in Nicaea (present-day Iznik, Turkey) to address the Arian controversy. The council condemned Arianism, which denied the full divinity of Jesus Christ, and produced the original Nicene Creed, affirming the consubstantiality of the Son with the Father.

First Council of Constantinople (381)

The First Council of Constantinople was held in 381 under the reign of Emperor Theodosius I. It expanded the Nicene Creed with additional descriptions of the Holy Spirit to combat the Macedonian heresy, which denied the divinity of the Holy Spirit. This council also affirmed the equality of the Father, the Son, and the Holy Spirit in the Trinity.

Council of Ephesus (431)

The Council of Ephesus convened in 431 to address the Nestorian controversy, which involved debates over the nature of Christ and the Virgin Mary. The council affirmed the title of Theotokos ("God-bearer") for Mary and upheld the unity of Christ's divine and human natures.

Council of Chalcedon (451)

The Council of Chalcedon was held in 451 to address the Monophysite controversy, which argued that Christ had only one nature, either divine or a synthesis of divine and human. The council declared that Christ is in two natures, fully divine and fully human, in one person and hypostasis.

Second Council of Constantinople (553)

The Second Council of Constantinople took place in 553, called by Emperor Justinian I. It dealt primarily with the reinterpretation of the Three Chapters, writings by theologians seen as Nestorian. The council condemned these writings to reconcile with the Monophysites, although it did not achieve this goal.

Third Council of Constantinople (680-681)

The Third Council of Constantinople occurred from 680 to 681, addressing the Monothelite controversy, which proposed that Christ had two natures but only one will. The council affirmed the doctrine of two wills in Christ, divine and human, corresponding to his two natures.

Second Council of Nicaea (787)

The Second Council of Nicaea was convened in 787 to address the iconoclast controversy, which involved debates over the veneration of icons. The council supported the veneration of icons, distinguishing it from the worship due to God alone.

These councils played a crucial role in defining key aspects of Christian doctrine, particularly concerning the nature of Christ, the Trinity, and the role of the Church. Their decisions are considered foundational for the theology and practice of the churches that recognize them.