The Seven Ecumenical Councils

The Orthodox Church recognizes seven Ecumenical Councils (325–787 AD) as the supreme expression of the Church’s conciliar authority in matters of faith and order. These Councils defined the central dogmas of Christianity – the Trinity and the Incarnation – and established canonical norms for the Church’s life. Their authority rests not on any external juridical principle but on their reception by the whole Church as authentic expressions of the apostolic faith.

Tradition: Pan-Orthodox

The Nature of Conciliar Authority

What Makes a Council Ecumenical?

In Orthodox ecclesiology, a council is ecumenical not simply because it was convened by an emperor, attended by bishops from across the known world, or even because it called itself ecumenical. A council’s ecumenicity is established by its reception – the acceptance of its decisions by the whole Church over time, guided by the Holy Spirit. Several councils that claimed ecumenical status were later rejected (e.g., the “Robber Council” of Ephesus in 449; the iconoclast councils of 754 and 815), while the councils recognized as ecumenical have been received as authentic witnesses to the apostolic faith.

As Lossky noted, this process of reception cannot be reduced to a juridical mechanism. It is an expression of the Church’s living Tradition – the Holy Spirit guiding the faithful into all truth (John 16:13) (Lossky, The Mystical Theology of the Eastern Church, ch. 1).

Councils Define, They Do Not Innovate

A fundamental Orthodox principle is that the Ecumenical Councils did not create new doctrines but defined what the Church had always believed, in response to specific heresies that threatened the integrity of the faith. Each council was occasioned by a crisis – a teaching that contradicted the received faith – and the council’s task was to articulate the apostolic truth with greater precision.

The Seven Councils

First Ecumenical Council: Nicaea I (325)

Location: Nicaea (modern Iznik, Turkey)
Convened by: Emperor Constantine I
Approximate number of bishops: Traditionally given as 318

Heresy Addressed: Arianism

Arius, a presbyter of Alexandria, taught that the Son of God was a creature – the highest of all creatures, but a creature nonetheless. His formula was: “There was [a time] when He was not” (en pote hote ouk en). The Son, for Arius, was not truly God but a being intermediate between God and creation.

Key Definition: Homoousios

The Council affirmed that the Son is homoousios (of one essence, consubstantial) with the Father – not merely homoiousios (of similar essence) or a creature. This term, which does not appear in Scripture, was adopted precisely because its precision excluded the Arian position. St. Athanasius, though a deacon at the Council (not yet a bishop), became the great champion of Nicene orthodoxy in the decades that followed (Athanasius, De Decretis Nicaenae Synodi; Orationes Contra Arianos).

The Nicene Creed

The Council produced the original form of the Nicene Creed, which includes the affirmation: “God of God, Light of Light, true God of true God, begotten not made, of one essence (homoousios) with the Father.”

Notable Canons

The Council promulgated 20 canons, including:

  • Canon 6: Affirmed the ancient privileges of the sees of Alexandria, Rome, and Antioch (a key text for later debates about ecclesiastical jurisdiction).
  • Canon 7: Recognized the Bishop of Aelia (Jerusalem) as holding a special position of honor.
  • Canon 13: Established that those in danger of death (in articulo mortis) should not be denied the Eucharist.
  • Canon 19: Addressed the readmission of followers of Paul of Samosata, requiring their re-baptism.
  • Canon 20: Prohibited kneeling on Sundays and during the days of Pentecost – the fifty days following Pascha (as a sign of the Resurrection).

Second Ecumenical Council: Constantinople I (381)

Location: Constantinople (modern Istanbul, Turkey)
Convened by: Emperor Theodosius I
Approximate number of bishops: 150

Heresy Addressed: Pneumatomachi (Macedonianism)

The Pneumatomachi (“Spirit-fighters”), associated with Macedonius, Bishop of Constantinople, denied the full divinity of the Holy Spirit. They accepted the Nicene definition regarding the Son but refused to extend the same affirmation to the Spirit, treating the Spirit as a creature or as an intermediate being.

Key Definition: The Divinity of the Holy Spirit

The Council affirmed the full divinity of the Holy Spirit, “the Lord, the Giver of Life, who proceeds from the Father, who with the Father and the Son together is worshipped and glorified.” The theological groundwork for this definition was laid by the Cappadocian Fathers, especially St. Basil the Great in his treatise On the Holy Spirit (Basil, De Spiritu Sancto; trans. NPNF II/8) and St. Gregory the Theologian in his Fifth Theological Oration (Oration 31).

The Nicene-Constantinopolitan Creed

The Council expanded and completed the Creed of Nicaea I, producing the Nicene-Constantinopolitan Creed that remains the baptismal and eucharistic creed of the Orthodox Church to this day. This is the Creed recited (or sung) at every Divine Liturgy.

Note on the Filioque: The original Creed states that the Holy Spirit “proceeds from the Father.” The Western addition of “and the Son” (Filioque), first introduced in Visigothic Spain (6th century) and gradually adopted throughout the West, was never accepted by the Orthodox Church and constitutes one of the central theological disputes between East and West.

Notable Canons

  • Canon 2: Prohibited bishops from intervening in the affairs of churches outside their own territory.
  • Canon 3: Declared that “the Bishop of Constantinople shall have the prerogative of honour after the Bishop of Rome, because Constantinople is the New Rome.” This canon, based on political rather than apostolic reasoning, was contested by Rome.
  • Canon 7: Specified procedures for receiving converts from various heretical groups – some by chrismation, others by baptism.

Third Ecumenical Council: Ephesus (431)

Location: Ephesus (modern Selcuk, Turkey)
Convened by: Emperor Theodosius II
Presided over by: St. Cyril of Alexandria

Heresy Addressed: Nestorianism

Nestorius, Patriarch of Constantinople, objected to calling the Virgin Mary Theotokos (“God-bearer” or “Mother of God”), preferring Christotokos (“Christ-bearer”). Behind this terminological dispute lay a deeper christological problem: Nestorius appeared to divide Christ into two separate subjects – a divine person (the Word) and a human person (Jesus) – united only by a moral or voluntary conjunction, not by a true ontological union.

Key Definition: Theotokos

The Council affirmed that Mary is rightly called Theotokos, because the one born of her is not merely a human person assumed by the Word but the incarnate Word Himself. This was not primarily a Mariological definition but a christological one: it safeguarded the unity of Christ’s person. The theological basis was laid by St. Cyril of Alexandria, whose Twelve Anathemas and Third Letter to Nestorius were approved by the Council (Cyril of Alexandria, Third Letter to Nestorius).

The Council also affirmed St. Cyril’s formula of the “hypostatic union” (henosis kath’ hypostasin) – that in Christ the divine and human natures are united in one person (hypostasis).

Notable Canons

  • Canon 7: Prohibited any alteration of the Nicene Creed – a canon later invoked by Orthodox against the Western Filioque addition.
  • Canon 8: Affirmed the autonomy of the Church of Cyprus against the claims of Antioch.

Fourth Ecumenical Council: Chalcedon (451)

Location: Chalcedon (modern Kadikoy, Turkey, across the Bosporus from Constantinople)
Convened by: Emperor Marcian
Approximate number of bishops: Approximately 520 (the largest of the ancient councils)

Heresy Addressed: Monophysitism (Eutychianism)

Eutyches, an archimandrite in Constantinople, reacted against Nestorianism by going to the opposite extreme. He taught that after the Incarnation, Christ had only one nature (mia physis) – the human nature being absorbed into or swallowed up by the divine, “like a drop of honey in the sea.” This effectively denied the full reality of Christ’s humanity.

Note: The non-Chalcedonian (Oriental Orthodox) churches – Armenian, Coptic, Ethiopian, Syriac, Malankara – reject the label “Monophysite” and describe their position as “Miaphysite” (one united nature), following St. Cyril’s formula “one incarnate nature of God the Word” (mia physis tou Theou Logou sesarkomene). The official Joint Commission of the Theological Dialogue produced two Agreed Statements (Anba Bishoy Monastery, 1989; Chambésy, 1990) concluding that both families “have always loyally maintained the same authentic Orthodox Christological faith” while using the terms differently; as of the mid-2020s, however, these statements have not received full synodal reception on either side, and communion has not been restored (Agreed Statements of the Joint Commission, 1989/1990).

Key Definition: The Chalcedonian Definition

The Council produced the famous Chalcedonian Definition (Horos), which states that Christ is:

“acknowledged in two natures, without confusion, without change, without division, without separation (en duo physesin asynchytos, atreptos, adiairetos, achoristos); the distinction of natures being by no means taken away by the union, but rather the property of each nature being preserved and concurring in one Person (prosopon) and one Subsistence (hypostasis), not parted or divided into two persons.”
(Council of Chalcedon, Definition of Faith; cf. trans. Tanner)

The four negative adverbs (without confusion, without change, without division, without separation) define the boundaries of orthodox Christology: against Eutyches (who confused or changed the natures) and against Nestorius (who divided or separated them).

Notable Canons

  • Canon 28: Granted Constantinople “equal privileges” (isa presbeia) with Rome and jurisdiction over Pontus, Asia, and Thrace, on the grounds that Constantinople was the imperial capital. This canon was protested by the Roman legates and was never accepted by Rome. It remains significant for Orthodox ecclesiology, grounding hierarchical prerogatives in ecclesiastical and political order rather than in apostolic foundation alone.
  • Canon 4: Prohibited monks from engaging in secular affairs or leaving their monasteries without the bishop’s permission.

Fifth Ecumenical Council: Constantinople II (553)

Location: Constantinople
Convened by: Emperor Justinian I
Approximate number of bishops: 165

Controversy Addressed: The Three Chapters

The Council addressed the so-called “Three Chapters” (tria kephalaia) – the writings or persons of three theologians associated with the Antiochene school who were suspected of Nestorian tendencies:

  1. Theodore of Mopsuestia – condemned posthumously as a person and in his writings
  2. Theodoret of Cyrrhus – certain writings against Cyril of Alexandria were condemned (though Theodoret himself had been rehabilitated at Chalcedon)
  3. Ibas of Edessa – his letter to Maris the Persian was condemned

The condemnation of the Three Chapters was intended to reconcile the non-Chalcedonian (Miaphysite) communities by demonstrating that Chalcedon did not endorse Nestorianism. In practice, this reconciliation largely failed.

Key Definition: Christological Precision

The Council reaffirmed the Chalcedonian Definition while interpreting it in a more explicitly Cyrillian direction. It affirmed that:

  • The one “who was crucified in the flesh” is “true God and Lord of glory and one of the Holy Trinity” – God the Word incarnate (Council of Constantinople II, Anathema 10; trans. Tanner)
  • Christ’s hypostasis is the pre-existing hypostasis of the Logos, not a new hypostasis formed by the union

The Council is also traditionally credited with condemning certain propositions attributed to Origen (pre-existence of souls, universal restoration/apokatastasis, the equality of all rational beings in the final state). [Disputed: the 15 anti-Origenist anathemas are absent from the official conciliar acts; Richard Price argues they were adopted at a preliminary session before the council formally opened (Price, The Acts of the Council of Constantinople of 553, Liverpool UP, 2009), while an earlier set of anti-Origenist anathemas belongs to Justinian’s edict and the local synod of 543. Orthodox tradition has nonetheless received the condemnation of Origenism as conciliar.]

Sixth Ecumenical Council: Constantinople III (680–681)

Location: Constantinople (held in the domed hall – troullos – of the imperial palace)
Convened by: Emperor Constantine IV
Approximate number of bishops: Approximately 170

Heresy Addressed: Monothelitism

Monothelitism (“one will”) was a compromise formula proposed to reconcile Chalcedonians and Miaphysites. It held that while Christ has two natures, He possesses only one will (thelema) and one energy/operation (energeia). The chief proponent was Patriarch Sergius I of Constantinople; it was also endorsed by Pope Honorius I of Rome, whom this Council condemned by name — a condemnation confirmed by Honorius’s successor Pope Leo II, and read by Orthodox theology as decisive witness that no see, Rome included, is exempt from the judgment of the Church in council, and therefore against the later Roman doctrine of papal infallibility (defined 1870), whose apologists read the case of Honorius otherwise.

Key Definition: Two Wills and Two Energies

The Council defined that Christ possesses two natural wills and two natural energies (operations), corresponding to His two natures – divine and human. The human will is not abolished or absorbed but is freely and perfectly conformed to the divine will:

“We proclaim equally two natural volitions or wills in him and two natural principles of action which undergo no division, no change, no partition, no confusion… his human will following, and not resisting or struggling, rather in fact subject to his divine and all powerful will.”
(Council of Constantinople III, Exposition of Faith; trans. Tanner)

The theological foundation for this definition was laid by St. Maximus the Confessor, who argued that the will is a property of nature, not of person. Since Christ has two complete natures, He must have two complete wills. To deny His human will would be to deny the completeness of His humanity and thus to undermine salvation: what is not assumed is not healed (Maximus the Confessor, Opuscula Theologica et Polemica; Disputatio cum Pyrrho).

Seventh Ecumenical Council: Nicaea II (787)

Location: Nicaea
Convened by: Empress Irene (as regent for her son Constantine VI)
Approximate number of bishops: Approximately 350

Heresy Addressed: Iconoclasm

The iconoclast movement, initiated under Emperor Leo III (c. 726) and given theological form by the iconoclast Council of Hieria (754), rejected the veneration of icons as idolatry. Iconoclasts argued that since Christ’s divine nature cannot be depicted, and since depicting only His human nature would imply a Nestorian separation of natures, icons of Christ are theologically impossible.

Key Definition: The Theology of Icons

The Council defended the veneration (proskynesis) of icons, distinguishing it sharply from the worship (latreia) due to God alone:

“We define with all certitude and accuracy that… the venerable and holy images… are to be set up in the holy churches of God… For the honour which is paid to the image passes on to that which the image represents (he tes eikonos time epi to prototypon diabainei), and he who reveres the image reveres in it the subject represented.”
(Council of Nicaea II, Definition; trans. NPNF II/14)

The theological foundation for icon veneration was provided by St. John of Damascus, who argued in his Three Treatises Against Those Who Attack the Divine Images that:

  1. The Incarnation itself is the ultimate justification of images: if God became visible in the flesh, He can be depicted in images (John of Damascus, De Imaginibus, I.16).
  2. The Old Testament prohibition of images was directed against idolatry and was conditioned by the historical situation before the Incarnation.
  3. Matter is not evil; it has been sanctified by the Incarnation and can serve as a vehicle of grace.

The icon is thus understood not as an arbitrary illustration but as a theological statement: it affirms the reality of the Incarnation. To reject icons is implicitly to deny that God truly became man.

The Quinisext (Trullo) Council (692)

Location: Constantinople (in the same domed hall – troullos – as the Sixth Council)
Convened by: Emperor Justinian II

The Quinisext Council (also called the Council “in Trullo”) was convened to provide canonical legislation for the Fifth and Sixth Ecumenical Councils, which had produced doctrinal definitions but few canons. The Council issued 102 canons covering a vast range of church discipline and practice.

Tradition: Pan-Orthodox (though the canons were never formally accepted in the West; Rome accepted some selectively)

Status

The Orthodox Church treats the canons of the Quinisext Council as having ecumenical authority, considering the Council a canonical supplement to the Fifth and Sixth Ecumenical Councils. In this understanding, the Fifth, Sixth, and Quinisext Councils together form a complete unit.

Notable Canons

  • Canon 2: Formally ratified the canons of previous councils and of specific Church Fathers (including the Apostolic Canons, the canons of local councils, and the canonical epistles of certain Fathers). This canon serves as a comprehensive canonical index.
  • Canon 13: Required that married men who are ordained deacons or priests must continue in their marriages, explicitly rejecting the Western practice of clerical celibacy for all clergy. This canon established the normative Orthodox discipline of married clergy (deacons and priests) alongside a celibate episcopate.
  • Canon 36: Renewed Canon 3 of Constantinople I and Canon 28 of Chalcedon regarding the rank of Constantinople, and listed the order of the patriarchal sees: Rome, Constantinople, Alexandria, Antioch, Jerusalem.
  • Canon 73: Prohibited the placement of the cross on floor pavements where it might be trodden upon.
  • Canon 82: Required that Christ be depicted in His human form rather than symbolically as a lamb – a significant canon for the theology and practice of iconography.

Summary Table

Council Year(s) Location Heresy Addressed Key Definition
Nicaea I 325 Nicaea Arianism Homoousios; Nicene Creed
Constantinople I 381 Constantinople Pneumatomachi Divinity of the Holy Spirit; expanded Creed
Ephesus 431 Ephesus Nestorianism Theotokos; hypostatic union
Chalcedon 451 Chalcedon Monophysitism Two natures “without confusion… without separation”
Constantinople II 553 Constantinople Three Chapters Cyrillian interpretation of Chalcedon
Constantinople III 680–681 Constantinople Monothelitism Two wills and two energies
Nicaea II 787 Nicaea Iconoclasm Veneration of icons; image theology

The Significance of the Councils for Russian Orthodox Theology

The Ecumenical Councils hold the same supreme dogmatic authority across all Orthodox churches. In the Russian tradition, the Councils have been central to theological education since the establishment of the Kiev and Moscow Academies. The Kniga Pravil (Book of Rules), the standard Russian canonical collection, includes the canons of all seven Ecumenical Councils along with those of the Quinisext Council and selected local councils.

The question of whether there can or should be an Eighth Ecumenical Council has been discussed in Orthodox theology. The Pan-Orthodox Council held in Crete in 2016 (the Holy and Great Council) was attended by representatives of most but not all autocephalous churches – notably, the Russian Orthodox Church and the Georgian, Bulgarian, and Antiochian churches declined to attend, so that ten of the fourteen universally recognized autocephalous churches participated (Statement of the Holy Synod of the Russian Orthodox Church, July 15, 2016; conciliar documents at holycouncil.org). Its status and authority remain under discussion.

See Also

References

  • Agreed Statements of the Joint Commission of the Theological Dialogue between the Orthodox Church and the Oriental Orthodox Churches (Anba Bishoy Monastery, 1989; Chambésy, 1990).
  • Athanasius of Alexandria. De Decretis Nicaenae Synodi; Orationes Contra Arianos.
  • Basil the Great. De Spiritu Sancto (On the Holy Spirit). Trans. NPNF II/8.
  • Cyril of Alexandria. Third Letter to Nestorius; Twelve Anathemas.
  • Davis, Leo Donald. The First Seven Ecumenical Councils (325–787): Their History and Theology. Collegeville, MN: Liturgical Press, 1990.
  • John of Damascus. De Imaginibus (Three Treatises Against Those Who Attack the Divine Images).
  • Lossky, Vladimir. The Mystical Theology of the Eastern Church. Cambridge: James Clarke, 1957.
  • Maximus the Confessor. Disputatio cum Pyrrho; Opuscula Theologica et Polemica.
  • Meyendorff, John. Imperial Unity and Christian Divisions: The Church 450–680 AD. Crestwood, NY: St. Vladimir’s Seminary Press, 1989.
  • Percival, Henry R., ed. The Seven Ecumenical Councils (NPNF II/14). Edinburgh: T&T Clark, 1900.
  • Price, Richard. The Acts of the Council of Constantinople of 553. 2 vols. Liverpool: Liverpool University Press, 2009.
  • The Rudder (Pedalion). Trans. D. Cummings. Chicago: Orthodox Christian Educational Society, 1957.
  • Tanner, Norman P., ed. Decrees of the Ecumenical Councils. 2 vols. Washington, DC: Georgetown University Press, 1990.