The Top Ten Most Important Church Councils

To be deep into history, John Henry Newman wrote, is to cease to be a Protestant. Put another way, to be deep into history is to become stronger in the Catholic faith—something we are all called to do in this Year of Faith.

To make that journey into the history of our faith is to discover anew its most basic tenets. Who was Jesus really? How can God be three persons in one being? What is the proper role of the Church in salvation? And how does Mary fit into all this?

These questions, and many more, were raised and answered in the ecumenical, or universal, Church councils.

Ironically, one key to understanding the orthodox teachings of these councils is heresy. The councils, especially the earliest ones, were essentially anti-heresy conventions, called to sort the wheat of dogma from the chaff of heresy. This could be a dizzying and disorderly process: no sooner had one bastion of orthodoxy had been defended, than the Church had to rush to the defense of another. So, while one council had to correct heretics who falsely divided Christ into two persons, the next council had to make a course correction in the other direction, reining in heretics who falsely united His human and divine natures into one.

“To have fallen into any one of the fads from Gnosticism to Christian Science would indeed have been obvious and tame,” G. K. Chesterton wrote in Orthodoxy. “But to have avoided them all has been one whirling adventure; and in my vision the heavenly chariot flies thundering through the ages, the dull heresies sprawling and prostrate, the wild truth reeling but erect.”

In all, there were 21 ecumenical councils. All were important in their time, but only some of them stand out for the lasting significance they have had on the faith and life of the Church today. Here, then, are the top ten must-know councils, listed chronologically by the date they were convened:

1. First Council of Nicaea, 325: One of the earliest heresies to rear its head was Arianism, which asserted that Christ was created by the Father and later adopted as His Son. Refuting this heresy—by declaring Christ one in being with the Father—was the chief task of the Council of Nicaea. In the process, the Nicene Creed was born. 

2. First Council of Constantinople, 381: This council defended dogma on two fronts. It affirmed the divinity of the Holy Spirit as the third person of the Trinity. And it condemned a new heresy that claimed Christ was part man and part God but not completely one or the other. Instead, the heresy, known as Apollinarism, put forward the harebrained theory that Christ was comprised of a human body and a divine mind.

3. Council of Ephesus, 431: This council defined the dogma that Christ is one person, not two persons, as the heretical Nestorians claimed. This council also has the distinction of being the only ecumenical gathering that made any dogmatic statements about Mary, declaring her to be the Theotokos, or Mother of God. The other great achievement of this council is its least known: repudiation of one of the most insidious of heresies in Christian history—Pelagianism, which denied original sin and said men can use their free will to attain salvation on their own merits, without God’s grace.

4. Council of Chalcedon, 451: After Ephesus declared that Christ was one person, some Christians took that teaching too far, concluding that He also had just one nature, a mystical blend of the human and divine (this heresy was known as Monophysitism, from the Greek words for one and nature). That obviously throws a wrench in the entire message of the gospel. If Christ wasn’t fully man, had mankind really been redeemed? If He wasn’t fully divine, had God really saved us? Needless to say, the Church quickly pulled together another council to clarify its earlier teaching: Christ was one person, but had two natures. The council ended up achieving more than it bargained for, in ways good and bad. On the upside, it helped to cement the primacy of the Pope as the leader of the Church. But it had the tragic and unintended consequence of sending the Orthodox churches in Syria, Egypt, and Ethiopia into schism.

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Stephen Beale


Stephen Beale is a freelance writer based in Providence, Rhode Island. Raised as an evangelical Protestant, he is a convert to Catholicism. He is a former news editor at and was a correspondent for the New Hampshire Union Leader, where he covered the 2008 presidential primary. He has appeared on Fox News, C-SPAN and the Today Show and his writing has been published in the Washington Times, Providence Journal, the National Catholic Register and on and A native of Topsfield, Massachusetts, he graduated from Brown University in 2004 with a degree in classics and history. His areas of interest include Eastern Christianity, Marian and Eucharistic theology, medieval history, and the saints. He welcomes tips, suggestions, and any other feedback at bealenews at gmail dot com. Follow him on Twitter at

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  • dmw

    When there are only 21 oecumenical councils anyway, why bother with creating a list of “the ten most important”? I would argue that you should have made at least the first seven as “most important” because they are the ones recognized by East and West alike. As a source of unity, breathing with both lungs, as you will, certainly all seven rank among the most important.

  • Rob B.

    I guess it isn’t technically a council, but I think the gathering of apostles and elders described in Acts 15 should make the list. After all, how many Gentiles would have converted in those early days if circumcision and avoiding pork were deemed necessary doctrines of the faith?

  • a

    What about the councils that decided the Canon of Scripture? Those would be a bit important?

  • Jason

    so happy that Vatican II wasn’t on the list actually. I’m sick of hearing about it as if it were the only council ever to happen.

  • See no. 8 – Council of Florence.

  • Matthew

    Have to disagree with the statement there has only been one infallible statement since VI. That comes from the idea that only dogmas can be defined infallibly and also a mistaken understanding of Vatican I that the Pope has to use the word “definit” which was carefully explained to the Council fathers at the time to not be the case by Bishop Gasser. Thus you have Sacramentum Ordinis defining the essential matter of the sacrament of order, Apostoliciae Cura on the invalidity of Anglican orders etc.

  • Ronk

    Indeed. And the mroe recent infallible declarations by Blessed John Paul II that abortion is absolutely always gravely immoral (Evangelium Vitae) and the absolute impossibility of the Church ever ordaining women to the priesthood. In the latter case, uniquely among infallible declarations the pope signed a later statement actually confirming that the previous statement was infallible.

  • The list of all those councils shows clearly how the church went away from the original Jewish faith and how the Catholic and many protestant beliefs deviated from the first apostolic belief in One Only True God and his son, the man from Nazareth, in the lineage from King David, Jeshua or Jesus Christ.