Your guide to the ecumenical councils of the Church

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Many sacred beliefs of our Catholic faith can be traced to the 21 ecumenical councils held since the fourth century. Called either an ecumenical (universal) or a general council, these terms are often used interchangeably. Councils consist of Church bishops from around the world gathering in response to a crisis, to affirm Church teachings or to address matters of faith, morals and even reform. Inspired by the Holy Spirit, these assemblies have continued to perpetuate the declaration Jesus made to Peter: “[A]nd upon this rock I will build my Church, and the gates of the netherworld shall not prevail against it” (Mt 16:18).

The first eight ecumenical councils were all held in the East, specifically the area we now know as Turkey. The other 13 were held in the West, at European locations.

The emperor, not the pope, called the first eight councils. The pope was typically consulted, invited or both, but mostly the Holy Father sent representatives or legates. The Second Vatican Council’s Dogmatic Constitution on the Church, Lumen Gentium, notes: “A council is never ecumenical unless it is confirmed or at least accepted as such by the successor of Peter; and it is the prerogative of the Roman Pontiff to convoke these councils, to preside over them and to confirm them” (No. 22). The 1983 Code of Canon Law spells out that the pope calls an ecumenical or general council; he presides over it or directs another to do so. The pope officially announces the council’s universal consent; the faithful then abide by the decisions.

The early councils in the East focused on protecting the divinity of Jesus, on the Trinity and man’s worship of his Creator. The most recent councils (within the last 500 years) have been dedicated to reforming the Church.

D.D. Emmons writes from Pennsylvania.




#1 Nicea (325)
Condemned Arianism, confirmed Divinity of Jesus, established Easter date

In the early fourth century, after Emperor Constantine ended religious persecutions, an Alexandrian priest named Arius was popularizing the heresy that Jesus was not equal to God the Father, not divine, that Jesus had a beginning, was created and not eternal. Arius and his followers conceived Jesus as a great prophet, but not God. Opposing Arius, defending the orthodox view that Jesus was divine and of the same substance as God the Father, was St. Athanasius, a cleric from Alexandria. The debate about the divinity of Jesus became so heated that Constantine advised Pope Sylvester I that he was calling a council of bishops to resolve the issue. Made up of 300 primarily Eastern bishops, this first ecumenical council, although not unanimously, condemned Arianism and excommunicated Arius. They developed the Nicean Creed, emphasizing Jesus as “Consubstantional with the Father … Begotten not made, one in being with the Father.” This language rejected Arianism and established clear teaching on Christ’s divinity. The bishops at Nicea also agreed to the date when Easter is celebrated.

#2 Constantinople I (381)
Condemned Arianism, Macedonianism; added Holy Spirit to Creed

In 381, Emperor Theodosius called all the bishops to Constantinople because Arianism remained widespread and also to confront another developing heresy. It appears that Pope St. Damasus was never notified about the council and only centuries later did the Holy See acknowledge the council as ecumenical. The 150 bishops attending reaffirmed the decisions of Nicea regarding Arianism and also condemned Macedonianism, a heresy denying the divinity of the Holy Spirit. The council proclaimed the Third Person of the Trinity as equal to the Father and the Son, and emphasized such belief by adding a clause to the Creed of Nicea: “We believe in the Holy Spirit, the Lord, the giver of life; he proceeds from the Father, is adored and honored together with the Father and the Son; he spoke through the prophets.” This language was accepted by the Eastern bishops and later in the West.

#3 Ephesus (431)
Rejected Nestorianism and claimed Mary as Mother of God

Around 428, Bishop Nestorius of Constantinople preached that Mary was not the Mother of God (Theotókos). He and others held that Jesus was two persons, one human, one divine, and that Mary gave birth to a human; thus Jesus was not God and Mary could not be the Mother of God. Against Nestorius, and supported by Pope St. Celestine I, was Bishop Cyril of Alexandria, who professed the Christian belief that Jesus was one person with two natures, one human, one divine. The arguments of Nestorius and Cyril were widely and passionately debated; at length, Emperor Theodosius II gathered the bishops at Ephesus where Nestorius was excommunicated and his teachings condemned. The 200 bishops confirmed Jesus was one person with two natures; that He was God and Mary was the Mother of God. Overjoyed upon hearing the decision, the people paraded through the streets chanting, “Holy Mary, Mother of God.”

” [W]e confess the holy virgin to be the Mother of God because God the Word took flesh and became man and from his very conception united to himself the temple he took from her.”
Council of Ephesus (431)

#4 Chalcedon (451)
Confronted Monophysitism and declared Christ had two natures

Chalcedon confronted the Monophysitism heresy, which held that Christ had one nature, that his human nature had been absorbed by the divine. Some heretics claimed that Jesus was not human at all. The council, invoked by Emperor Marcian, was attended by as many as 600 bishops, the largest gathering at a general council to date. The council had full approval of Pope St. Leo the Great, who sent a letter condemning the one nature theory; the bishops affirmed that Jesus possessed two natures, fully human and fully divine.

#5 Constantinople II (553)
Affirmed decisions of early councils, condemned supporters of Nestorianism

The bishops were summoned by Emperor Justinian I in 553 to reaffirm the decisions of the previous councils, especially that Jesus had two natures and that followers of Nestorius were teaching heresy. Pope Vigilius was invited to attend but sent representatives, adding to some 150 bishops, almost all from the East. The council anathematized certain writings of Theodoret of Cyr, Theodore of Mopsuestia and Ibas of Edessa. Their works, supporting Nestorianism and written 100 years earlier, were known as the “Three Chapters.”

#6 Constantinople III (680-81)
Decreed that Jesus had two wills

Summoned by Emperor Constantine IV, with approval of Pope St. Agatho, this council dealt with the contention that Jesus did not have two wills, one human and one divine. The heretics claimed he had only one will, a divine will. The 175, mostly eastern, bishops rejected the idea of one will (called Monothelitism) and decreed that Christ had “two natural wills without division, without change, without separation, without confusion.” Those who supported the heresy, including Pope Honorius I, were condemned.

#7 Nicea II (787)
Denied Iconoclasm, encouraged veneration of images

In 730, Emperor Leo III had demanded that images in worship places be removed, asserting that the use of statues, pictures and icons was idolatry. Denying the veneration of images became known as iconoclasm and was opposed at this council summoned by Empress Irene. The council’s 300 bishops, including representatives of Pope Adrian I, ruled that veneration of an image was directed to the holy person the image represented, not the image itself.

#8 Constantinople IV (869-70)
Photius rejected as Patriarch of Constantinople

In the ninth century two individuals were claiming the position of Patriarch of Constantinople. Depending on the emperor, and to some decree the pope, either Ignatius or Photius held that role. In 867, after being deposed by Pope St. Nicholas I, Photius presided over a local council of bishops that excommunicated the pope and condemned certain Western beliefs, including the Filioque that Rome had added to the Creed. Shortly after becoming emperor, Basil summoned a general council to sort out the true patriarch. At the Fourth Council of Constantinople in 869 (the eighth ecumenical council) with some 100 bishops present, all the decisions of the earlier local council in 867 were rejected; the attending bishops anathematized Photius and demanded that everyone consecrated by Photius be removed from office. The Eastern Church has never accepted the council of 869 as ecumenical, maintaining that Nicea was the last ecumenical council. In 877, the emperor reinstated Photius as Patriarch of Constantinople.




#9 Lateran I (1123)
Condemned lay investiture

The first Lateran Council, held at the Palace of Lateran in Rome, was called by Pope Callistus II with 300 bishops attending. The attendees affirmed and decreed that a monarch did not have the authority to bestow spiritual powers on a bishop; such authority was reserved for the Church. The intent was to end the so-called lay investiture, which permitted a king to invest a bishop with both temporal and spiritual powers. Among other decisions, crusaders were granted indulgences for their service, simony was prohibited and a priest could not marry once ordained.

#10 Lateran II (1139)
Renounced acts of antipope Anacletus

Lateran II took place 16 years later, and as many as 500 bishops met in the same location. Upon the death of Pope Honorius II in February 1130, a few cardinals quickly and secretly elected Innocent II as pope. Other cardinals, appalled by the covert action, elected a different pope, Anacletus II. Now there were two popes who considered themselves duly elected, and a chaotic situation lasted until Anacletus died in 1138. The next year, Innocent II convoked the Second Lateran Council, where all the acts and consecrations of Anacletus were annulled and his supporters condemned.


#11 Lateran III (1179)
Papal elections

Papal elections were the main focus of this council called by Pope Alexander III. At the time, there was little clarity as to how a pope was elected, with many advocating for a unanimous vote of the College of Cardinals, but such a vote was most unlikely. Lateran III decided that a two-thirds vote was necessary for a papal election, and anyone disagreeing with the election would be excommunicated. The attendees also decreed that the courtroom testimony of a Christian was to be believed over that of a Jew. The minimum age for ordination was established and members of the heretical Waldenses and Albigenses, who professed beliefs counter to the Church, were condemned. These groups would be later eradicated during a European crusade.

#12 Lateran IV (1215)
Annual participation in the sacraments of Eucharist and Confession

Taking only three sessions, this is among the most renowned of all Church Councils. Called by Innocent III, more than 400 bishops decreed that Catholics were obligated to receive the sacraments of Eucharist and Penance at least once a year during the Easter season. The term “transubstantiation” (change in substance) was promoted to describe the miracle taking place when the bread and wine become the body and blood of Christ.

#13 Lyon I (1245)
Excommunicated King Fredrick II

There had long been a struggle between the pope and temporal rulers. A 13th-century antagonist was King Fredrick II of Germany, who defied Pope Gregory IX at every opportunity and was excommunicated more than once. Seeking to make the papacy part of his monarchy, Fredrick continuously opposed the Holy Father. The pope called for a council at Rome in 1241 in large measure to deal with the obstinate king, but Frederick kidnapped over 100 bishops sailing to Rome. Pope Gregory died that year and confronting the king fell to Pope Innocent IV, who in 1245 called for a general council at Lyon, France. While other issues were discussed, the focus was on Fredrick, who was accused of numerous actions against the pope, of heresy and of kidnapping the bishops, and he was considered an enemy of the Church. The 150 bishops deposed the king; no Christian was obligated to give him their obedience.

#14 Lyons II (1274)
Reunion of East and West, Filioque, papal elections

Focused on reunion between Eastern and Western Churches, this council was summoned by Blessed Pope Gregory X in 1274. Eastern Church attendees accepted the primacy of the pope as leader of the Church and the amendment to the Nicean-Constantinoplian Creed regarding the Holy Spirit, “Who proceeds from the Father and the Son,” (the Filioque) long objected to by the East. These were major concessions, but short-lived because, when the Eastern representatives returned home, support for their actions fell apart. These issues still divide much of the East and West. The council also dealt with the issue of prolonged papal vacancies and decreed that a conclave should begin within 10 days after a pope’s death.

#15 Council of Vienne (1311-12)
Suppressed the Knights Templar

Pope Clement V called the council in response to pressure from King Philip IV of France. Among other demands, Philip wanted the Knights Templar condemned and disbanded. The Templars were Christian soldiers organized and committed to protecting pilgrims going to the Holy Land. They took monastic vows, had grown out of the First Crusade and become powerful, influential and very wealthy. King Philip desperately needed funds so he was after the group’s wealth. He first had numerous Templars arrested and through torture got them to confess to crimes they may or may not have committed. Pope Clement, fearful of Philip, had selected the under-300 bishops in attendance. The Templars were not allowed to defend themselves, and Clement acted pretty much unilaterally in using the charges of Philip to disband the group.

#16 Constance (1414-18)
Election of Pope Martin V, conciliarism

From 1378 until 1417, Catholics had two popes; one Roman and one from Avignon, France, where the Holy See had relocated for a period of 70 years. The cardinals first elected Urban VI, but some quickly became disenchanted with their choice. Many of the cardinals moved to France where they invalidated the election of Urban and elected Clement VII, so there were two lawfully elected popes. Naturally each pope set up their own papacy and selected bishops and cardinals. In 1409, the cardinals, disgruntled with the problem, elected a third pope. This chaos resulted in a general council being called at Constance, Switzerland,in 1414. Early on, each of the popes either resigned or was deposed, and the bishops elected Martin V as pope. The bishops also decreed that a general council was forthwith supreme over a pope: “… [I]t [the council] has power immediately from Christ; and that everyone of whatever state or dignity, even papal, is bound to obey it in those matters which pertain to the Faith.” Attendees decreed that future councils would be held at regular intervals, the next within five years after Constance. Pope Martin approved the acts of the council except for a pope being subject to a council (conciliarism).

#17 Basel, Ferrara, Florence (1431-45)
Reestablished pope over general council, attempted reconciliation between East and West

Pope Martin attempted to call a council five years following Constance, but because of widespread wars, not enough bishops could attend. Martin died, and while Pope Eugene IVopened a council in Basel in December 1431, thinking the situation was unruly, he quickly sought to dissolve it. Bishops wanted the council to continue and tried to invoke the rejected decree made at Constance that a council was superior to a pope. Eugene refused, as no pope had ever approved such a decree. A stalemate ensued, and the bishops at Basel elected antipope Felix V. In 1438, after a failed attempt at Ferrara, Italy, a council was opened in Florence. In the end, the Byzantine representatives accepted the Western language in the creed and supremacy of the pope. But, as had happened before, not everyone in Constantinople accepted the results, and the split between East and West remained. The bishops defined belief in purgatory. Felix later resigned, and the role of the pope over a council endured until questioned again in 1511.

#18 Lateran V (1512-17)
Roles of pope and general council

A resurgence of conciliarism resulted from an unrecognized council held at Pisa, Italy, in 1511. With only 15 bishops attending, and erroneously called by King Louis XII of France, the bishops declared a general council ruled over a pope. No pope had ever agreed to such a decree. As a result, Pope Julius II summoned a general council to be held in the Palace of Lateran in 1512. Julius died before the council began, and it was presided over by Pope Leo X. The Lateran Council rejected all the decisions made at Pisa. The bishops also decreed that a crusade be conducted against the Turks; but no crusade was ever carried out. While the council lasted five years, little else was accomplished.



#19 Trent (1545-63)
Rejected the Protestant Reformation, affirmed Church teachings, implemented reforms

Lasting 18 years, due to wars and plagues, the Council of Trent was called in reaction to the 16th-century Protestant Reformation. This was a crisis; it was a schism in Christianity that has never healed. The council confirmed Catholic beliefs in view of the heretical teachings of the excommunicated Martin Luther and implemented long overdue internal reforms. For 200 years, the Church had been aware of needed reforms but for various reasons failed to act in a definitive way. Many of the council reforms were directed at the clergy — their recruitment, training, lifestyle and obligation to remain celibate. Bishops were limited to control of one diocese and had to reside therein. The preparation of a catechism was directed. In response to the Protestants, the council affirmed and solidified the sacred teachings of the Church including the Mass, purgatory, justification, the Seven Sacraments, that Divine Revelation comes from both Scripture and Tradition, that Church teachings on the Bible are infallible and that the books in the Bible are inspired by God. The practice of indulgences was continued but selling of indulgences condemned. While Pope Paul III convoked the council, four other popes would be elected during the council. As few as 30 and as many as 200-plus bishops attended the council’s 25 sessions.

“Indeed, the very ancient practice whereby bishops … were in communion with one another and with the Bishop of Rome in a bond of unity, charity and peace, and also the councils assembled together, in which more profound issues were settled in common, the opinion of the many having been prudently considered, both of these factors are already an indication of the collegiate character and aspect of the Episcopal order.”
‘Lumen Gentium,‘ Dogmatic Constitution on the Church of the Second Vatican Council (1964, No. 22)

#20 Vatican I (1869-70)
Papal Infallibility

Summoned by Blessed Pius IX, the council of 800 bishops provided the pope with infallibility, declaring, “It is divinely revealed dogma that the Roman Pontiff, when he speaks ex cathedra, that is, when, acting in the office of shepherd and teacher of all Christians, he defines, by virtue of his supreme apostolic authority, a doctrine concerning faith or morals to be held by the universal Church.” In addition to establishing papal infallibility, the bishops condemned liberalism, pantheism, materialism and issued a constitution on faith and revelation.

#21 Vatican II (1962-65)
Promoted Christian unity, addressed the role of the Church in the 20th century

This was generated to be a reforming council. Convoked by Pope St. John XXIII, with over 2,800 attendees, this was the largest ever ecumenical council. The liturgy was revised, the role of the laity was expanded, ecumenism was urged and Catholics were challenged to increased witnessing of the Faith. There was belief that needed fresh air would begin blowing in the Church. As time moves the Church further and further away from Vatican II, initial confusion and uncertainty have stabilized, and fewer and fewer of the faithful have experienced Catholicism before the most recent of the 21 ecumenical councils.


D.D. Emmons

D.D. Emmons writes from Pennsylvania.