A cardinal excommunicates a patriarch in Hagia Sophia, and a thousand years of division follow. Is that really what happened?
Short answer: The Great Schism was not caused by one day in 1054. East and West had drifted apart for centuries over language, politics, customs, the filioque, and above all the authority of the pope. The excommunications of 1054 became its symbol, and the sack of Constantinople in 1204 sealed it. Both sides share the blame for the sins of the schism, but not for the truth of the doctrine: the deepest question is still St. Peter's role, and on that Scripture and the Fathers speak for Rome.
Key verses on unity and reconciliation
- "so that they may all be one" (John 17:21)
- "leave your gift there at the altar, go first and be reconciled with your brother" (Matthew 5:24)
- "For the kingdom of God is not a matter of food and drink" (Romans 14:17)
- "striving to preserve the unity of the spirit through the bond of peace" (Ephesians 4:3)
- "once you have turned back, you must strengthen your brothers" (Luke 22:32)
Scripture quotations are from the New American Bible, Revised Edition (NABRE), © 2010, 1991, 1986, 1970 Confraternity of Christian Doctrine, Washington, D.C. Used by permission. All rights reserved.
What Catholics Actually Teach
The Church does not tell this as innocent Rome against rebellious Constantinople. Separations happened "for which, often enough, men of both sides were to blame" (CCC 817). Vatican II explained that the apostolic heritage "was received with differences of form and manner," and that this, "quite apart from external causes, prepared the way for decisions arising also from a lack of charity and mutual understanding" (Unitatis Redintegratio 14).
The Church also teaches that the Orthodox are close: "this communion is so profound 'that it lacks little to attain the fullness that would permit a common celebration of the Lord's Eucharist'" (CCC 838).
What Catholics do not teach:
- That 1054 excommunicated the whole Eastern Church. The sentences targeted persons: Humbert's bull excommunicated "Patriarch Michael and all his followers" (as the Orthodox Church in America summarizes it), and Cerularius excommunicated the legates.
- That Eastern customs are defective. Leavened bread, married priests, and Greek liturgy are legitimate.
- That Latin Christians were blameless. In 2001 Pope St. John Paul II said in Athens: "For the occasions past and present, when sons and daughters of the Catholic Church have sinned by action or omission against their Orthodox brothers and sisters, may the Lord grant us the forgiveness we beg of him" (Address to Archbishop Christodoulos).
The long drift
Language. The West thought and prayed in Latin, the East in Greek, and fewer leaders could read each other's theology.
Politics. The Roman Empire split. In 800, Pope St. Leo III crowned Charlemagne emperor in the West, which Constantinople saw as a rival claim. Later, Norman conquests in southern Italy, where Greek and Latin churches met, added tension.
The Photian controversy (863–867). A dispute over who was rightful patriarch of Constantinople became a clash over papal authority and the filioque. Communion was later restored, but the arguments remained.
The filioque. The West added "and the Son" to the Creed. The East saw an unauthorized change. The doctrine itself was not new in the West: "Pope St. Leo I, following an ancient Latin and Alexandrian tradition, had already confessed it dogmatically in 447" (CCC 247). (See The Filioque: Does the Spirit Proceed from the Father and the Son?)
The papacy. Rome understood its primacy as real authority over the whole Church. Many in the East saw it as a primacy of honor. Orthodox writers say so plainly: the Orthodox Church in America calls "the reassertion of Papal claims" the "biggest single reason for the Great Schism" (The Orthodox Faith, vol. 3). Catholics agree that this is the real issue, which is why it must be settled from Scripture.
The events of 1054
In the early 1050s, Patriarch Michael Cerularius ordered Latin churches in Constantinople to adopt Greek usages and closed those that refused. Archbishop Leo of Ohrid attacked Latin customs, especially the use of unleavened bread at Mass. Pope St. Leo IX sent legates led by Cardinal Humbert of Silva Candida. Talks failed. St. Leo IX died on April 19, 1054, but the legates carried on. On July 16, 1054, Humbert excommunicated Cerularius in Hagia Sophia. Cerularius and his synod excommunicated the legates in return.
After 1054
The break hardened slowly. The worst wound came in 1204, when Crusaders sacked Constantinople. St. John Paul II called it "the disastrous sack of the imperial city of Constantinople" and said "The fact that they were Latin Christians fills Catholics with deep regret." Reunions were agreed at Lyons (1274) and Florence (1439), but neither lasted.
In 1965, Pope St. Paul VI and Patriarch Athenagoras I declared that they "commit these excommunications to oblivion" (Joint Catholic-Orthodox Declaration).
The Biblical Case
1. Christ wills one visible flock
Jesus prayed "that they may all be one... that the world may believe that you sent me" (John 17:21). St. Paul urged believers to keep "the unity of the spirit through the bond of peace" (Ephesians 4:3). Division is a wound, not a normal state.
2. Rites can differ; charity must not
The argument over leavened and unleavened bread was not frivolous. The Last Supper fell during "the feast of Unleavened Bread" (Luke 22:7), and St. Paul speaks of "the unleavened bread of sincerity and truth" (1 Corinthians 5:8). But St. Paul also wrote: "The one who eats must not despise the one who abstains" and "the kingdom of God is not a matter of food and drink" (Romans 14:3, 17). The Council of Florence settled it: "the body of Christ is truly confected in both unleavened and leavened wheat bread" (Florence, Session 6).
3. Reconcile before the altar
Jesus said: "if you bring your gift to the altar, and there recall that your brother has anything against you, leave your gift there at the altar, go first and be reconciled with your brother" (Matthew 5:23–24). In 1054 men on both sides did the opposite.
4. St. Peter's ministry of unity
The deepest issue is St. Peter. Jesus gave him "the keys to the kingdom of heaven" (Matthew 16:19), prayed that his faith would not fail, and told him, "you must strengthen your brothers" (Luke 22:32). He charged him: "Feed my sheep" (John 21:17). Catholics hold that the pope "is the perpetual and visible source and foundation of the unity both of the bishops and of the whole company of the faithful" (CCC 882). Full case: Is the Papacy in the Bible?
Scripture also shows what happens without a visible center. At Corinth, factions lined up behind St. Paul, Apollos and Cephas, and St. Paul asked whether Christ Himself had been divided (1 Corinthians 1:12–13). The first-century answer to that schism came from Rome: Pope St. Clement I (St. Clement of Rome) wrote to Corinth around AD 96 and warned that those "disobedient unto the words spoken by Him through us" would "entangle themselves in no slight transgression and danger" (1 Clement 59, Lightfoot translation).
Objections Answered
(a) "Rome caused the schism by claiming power it never had."
At its strongest: In the Orthodox view, the early Church was a communion of sister churches under ecumenical councils. Rome had first place in honor, but popes gradually claimed jurisdiction over the East and backed the filioque on their own authority. Humbert's bull, issued after the pope who sent him had died, shows that overreach.
Answer: Catholics need not defend Humbert; a legate's conduct is not the papacy. But Rome's role did not begin in the eleventh century, and it did not begin in Rome. It began with Christ's words to St. Peter: the keys (Matthew 16:19), "strengthen your brothers" (Luke 22:32), "Feed my sheep" (John 21:17). Around AD 110, St. Ignatius of Antioch, an Eastern bishop, greeted the Roman Church as the one "which presides over love." Around 180, St. Irenaeus wrote that "every Church should agree with this Church, on account of its preeminent authority" (Against Heresies 3.3.2). In AD 451 the bishops of Chalcedon, nearly all Eastern, heard Pope St. Leo the Great's letter and cried: "Peter has spoken thus through Leo." In 681 the Third Council of Constantinople wrote to Pope St. Agatho: "Therefore to thee, as to the bishop of the first see of the Universal Church, we leave what must be done" (Letter of the Council to St. Agatho). Rome did not invent its claim in 1054. The East had heard it, and often welcomed it, for centuries.
(b) "The excommunications were lifted in 1965, so the schism is over."
At its strongest: If the sentences of 1054 were committed "to oblivion," what still divides us?
Answer: The 1965 declaration itself said this gesture "is not sufficient to end both old and more recent differences." Lifting the sentences healed memories. It did not settle the papacy, the filioque, purgatory, divorce and remarriage, or the later councils. Christ's standard is higher than mutual pardon: "one flock, one shepherd" (John 10:16), one table, one faith.
(c) "1054 was only about bread and politics, so the differences don't matter."
At its strongest: Many disputes, like unleavened bread, were about customs. Surely Christians could reunite by ignoring them.
Answer: Florence settled the customs: both breads are valid. What remains is doctrine: who has authority to decide disputes for the whole Church? In Acts, "The apostles and the presbyters met together," and after much debate St. Peter rose to speak (Acts 15:6–7). The decisions were then handed on "to the people for observance" in city after city (Acts 16:4). A Church that cannot decide its disputes as one cannot do what the Church of Acts did. The structure of unity matters.
The Early Church Agrees
- St. Ignatius of Antioch (Letter to the Romans, prologue, c. AD 110): the church "which also presides in the place of the region of the Romans... and which presides over love".
- St. Cyprian of Carthage (Epistle 54 14, c. AD 252), on schismatics who appealed to Rome: they sailed "to the throne of Peter, and to the chief church whence priestly unity takes its source".
- Council of Chalcedon (AD 451), after Pope St. Leo the Great's letter was read: "Peter has spoken thus through Leo."
- St. Maximus the Confessor (seventh century), a Greek monk the Orthodox venerate, as quoted in the Catechism: "all Christian churches everywhere have held and hold the great Church that is here [at Rome] to be their only basis and foundation" (CCC 834).
- St. John Chrysostom (Homily 11 on Ephesians, late fourth century), the great Eastern preacher: "Nothing so provokes God's anger as the division of the Church."
Conclusion
The Great Schism was a slow tragedy of misunderstanding, pride, politics, and real disagreement. Both sides sinned. Both kept the sacraments and much of the apostolic faith, but the gifts the Orthodox preserve draw their power "from the fullness of grace and truth that Christ has entrusted to the Catholic Church" and "are in themselves calls to 'Catholic unity'" (CCC 819).
If you are Orthodox, we do not ask you to forget your history or your saints. We ask you to consider whether St. Peter's ministry, which the Fathers of East and West honored, is the gift that can make us one again. Learn more in What Is the Difference Between Catholic and Orthodox?
Come home. The schism grew from wounded charity and a dispute over St. Peter's role, and it can be healed only where St. Peter's ministry of unity still stands: in the Catholic Church. You already possess true sacraments and much of the apostolic faith, in "a certain, although imperfect, communion with the Catholic Church" (CCC 838). Those gifts draw their power "from the fullness of grace and truth that Christ has entrusted to the Catholic Church" and "are in themselves calls to 'Catholic unity'" (CCC 819). The Eucharist is the sacrament of the Church's unity, yet your true Eucharist is celebrated apart from the successor of St. Peter, on whom Christ built His Church (Matthew 16:18). We invite you into full communion with St. Peter's successor, the bishop of Rome, in the Catholic Church.
Your next step: Come to Mass or Divine Liturgy at your local Catholic church. You can find one near you at MassTimes.org. When you're ready, call the parish office and ask to speak with the priest about entering full communion with the Catholic Church. Read our guide: How Do I Become Catholic? Not ready yet? Get our free pocket guide below and keep learning.
FAQ
Who excommunicated whom in 1054? Cardinal Humbert excommunicated Patriarch Michael Cerularius on July 16, 1054; Cerularius then excommunicated the legates.
Was the pope alive when the excommunication happened? No. Pope St. Leo IX had died on April 19, 1054.
Are Catholics and Orthodox still divided? Yes. The 1965 declaration removed the excommunications, but full communion has not been restored.
Sources
Scripture (NABRE, bible.usccb.org): Matthew 5:23–24; Matthew 16:18; Matthew 16:19; Luke 22:7; Luke 22:32; John 10:16; John 17:21; John 21:17; Acts 15:6–7; Acts 16:4; Romans 14:3, 17; 1 Corinthians 1:12–13; 1 Corinthians 5:8; Ephesians 4:3.
Catechism of the Catholic Church (vatican.va): 247; 817, 819, 834, 838; 882.
Church documents: Second Vatican Council, Unitatis Redintegratio 14; Pope St. Paul VI and Athenagoras I, Joint Catholic-Orthodox Declaration (December 7, 1965); Pope St. John Paul II, Address to Archbishop Christodoulos, Athens (May 4, 2001); Council of Florence (1439), Session 6 (EWTN Library).
Orthodox sources (oca.org): The Orthodox Faith, vol. 3, "The Great Schism".
Church Fathers and councils (newadvent.org unless noted): Clement of Rome, 1 Clement 59 (Lightfoot translation, earlychristianwritings.com); Ignatius of Antioch, Letter to the Romans; Irenaeus, Against Heresies 3.3.2; Cyprian, Epistle 54; Council of Chalcedon (451); John Chrysostom, Homily 11 on Ephesians; Third Council of Constantinople (681), Letter of the Council to St. Agatho (ccel.org). Maximus the Confessor as quoted in CCC 834.
History: Britannica, "Michael Cerularius"; Britannica, "Saint Leo IX"; Britannica, "Schism of 1054"; Wikipedia, "East–West Schism".