In April 1204, an army of Latin Christians broke into Constantinople, looted Hagia Sophia, and spilled Christian blood. For many Orthodox, that is the real date the Churches split. Is it?
Short answer: No, though it deepened the wound more than any other event. The sack of Constantinople was a grave sin, and the Catholic Church says so: Pope Innocent III condemned it, and Pope St. John Paul II, naming it, asked forgiveness for Catholics' sins against the Orthodox. But the schism's roots go back centuries before 1204, to the Photian controversy, the filioque, and above all the authority of the bishop of Rome. The crusaders' sins hardened the division; they did not change who St. Peter's successor is, or the Church Christ built on him, the Catholic Church.
Key verses on unity and repentance
- "so that they may all be one, as you, Father, are in me and I in you" (John 17:21)
- "you are Peter, and upon this rock I will build my church" (Matthew 16:18)
- "I have prayed that your own faith may not fail; and once you have turned back, you must strengthen your brothers." (Luke 22:32)
- "Put your sword back into its sheath, for all who take the sword will perish by the sword." (Matthew 26:52)
- "go first and be reconciled with your brother, and then come and offer your gift." (Matthew 5:24)
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 the Orthodox Believe
Orthodox historians do not usually say that 1204 alone created the schism. They say something stronger: that 1204 made it permanent in the hearts of the Orthodox people.
The Orthodox Church in America's history describes it this way: "the knights of the Fourth Crusade brutally sacked Constantinople" in 1204. "They pillaged Hagia Sophia and other churches, desecrating the altars." Then "A Latin, Thomas Morosini, was named Patriarch of Constantinople." The result: "Now, for the first time, the entire Latin West became a deeply hated enemy in the minds of the Greek people." For this reason, the OCA says, the thirteenth century "began with what is generally considered to be the final sealing of the schism between East and West."
Elsewhere the same history explains that before 1204, "the reality and extent of the schism gradually deepened and spread," and that "the sack of Constantinople and its conquest by the Latin knights of the Fourth Crusade in 1204" "increased the mutual animosity to such a degree that future efforts at reconciliation had virtually no chance" of success. Yet it names something else as the root: "the biggest single reason for the Great Schism was the reassertion of Papal claims."
The argument at its strongest runs like this: Rome claimed universal authority; Rome's own crusaders then sacked the Queen of Cities and installed a Latin patriarch over her. Is that not what papal supremacy looks like in practice? Why would any Orthodox Christian submit to it?
What Catholics Actually Teach
First, we concede everything that is true, and that is a great deal.
The sack was a sin, and Rome said so at the time. Before the crusaders attacked the Christian city of Zara in 1202, Pope Innocent III sent letters to Venice forbidding it (Britannica). The crusaders afterward had to seek absolution for taking Zara, and Innocent finally excommunicated the Venetians who had turned the crusade from its purpose (Catholic Encyclopedia; see the history sources below). When he heard of the sack of Constantinople, he wrote to his legate Cardinal Peter of St. Marcellus that the crusaders, "whose swords, which they were supposed to use against the pagans, are now dripping with Christian blood," had exposed "both matrons and virgins, even those dedicated to God, to the sordid lusts of boys," and "laid their hands on the treasures of the churches." The Greek Church, he wrote, sees "in the Latins only an example of perdition and the works of darkness, so that she now, and with reason, detests the Latins more than dogs" (Innocent III, letter to Cardinal Peter). "With reason." A pope said that.
The Catholic Church has asked forgiveness. In Athens in 2001, Pope St. John Paul II said: "I am thinking of the disastrous sack of the imperial city of Constantinople, which was for so long the bastion of Christianity in the East," and "The fact that they were Latin Christians fills Catholics with deep regret." Then: "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). In 2004, welcoming Ecumenical Patriarch Bartholomew I to Rome, he said "we cannot forget what happened during the month of April 1204. An army that had set out to recover the Holy Land for Christendom marched on Constantinople, took it and sacked it, pouring out the blood of our own brothers and sisters in the faith. Eight centuries later, how can we fail to share the same indignation and sorrow that Pope Innocent III expressed as soon as he heard the news of what had happened?" (Welcome Address to Bartholomew I).
Both sides sinned in the long separation. The Catechism says the great divisions arose in ways "for which, often enough, men of both sides were to blame" (CCC 817).
But the Catholic Church also teaches what the sins of her members cannot touch. "Christ always gives his Church the gift of unity," and that unity "subsists in the Catholic Church as something she can never lose" (CCC 820). 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," and he holds that office "by reason of his office as Vicar of Christ" (CCC 882), not by the merits of any army.
What Catholics do not teach:
- That the sack was justified. Innocent III condemned it, and Pope St. John Paul II expressed deep regret and shared his indignation and sorrow.
- That the pope ordered it. The crusade was diverted by Venetian debts and Byzantine dynastic politics, against papal prohibitions and protests. Innocent III did afterward try to make the best of the new Latin Empire, a policy that deepened Greek bitterness; we do not hide that.
- That the papacy is proven by the conduct of Latins. It is proven by Christ's words to St. Peter, and it stands despite our sins.
It all points to Christ. The papacy exists because Christ prayed for St. Peter and charged him to "strengthen your brothers" (Luke 22:32). It is Christ's gift for the unity He prayed for, "so that they may all be one" (John 17:21). When Latins wielded swords against their brothers, they betrayed Christ and the very office they claimed to serve. The remedy for that betrayal is not to abandon Christ's gift, but to return to it together.
The Biblical Case
1. The schism did not begin in 1204
Dates matter. In 863–867, the Photian controversy set Rome and Constantinople against each other over the patriarchal throne, papal authority, and the filioque. On July 16, 1054, Cardinal Humbert excommunicated Patriarch Michael Cerularius in Hagia Sophia, and Cerularius returned the sentence (see What Caused the Great Schism of 1054?). The OCA itself names "the reassertion of Papal claims" as the "biggest single reason." That is a question about Christ's words to St. Peter, and it was being argued centuries before any crusader reached the Bosphorus. A sin committed in 1204 cannot be the cause of a disagreement already centuries old.
2. Unworthy servants do not cancel God's gifts
Scripture is clear that human infidelity does not undo divine fidelity. "What if some were unfaithful? Will their infidelity nullify the fidelity of God? Of course not!" (Romans 3:3–4). St. Peter himself denied Christ three times, yet in the very passage where Jesus foretells it, He says: "I have prayed that your own faith may not fail; and once you have turned back, you must strengthen your brothers" (Luke 22:31–32). Christ gave St. Peter his office knowing he would fall. If St. Peter's own sin did not revoke it, the crusaders' sins did not either.
3. Christ built His Church on St. Peter, not on Christians' behavior
"And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it. I will give you the keys to the kingdom of heaven" (Matthew 16:18–19). The risen Lord renewed the charge: "Feed my sheep" (John 21:17). The promise rests on Christ's word. The Orthodox venerate the same Fathers who heard that word as applying to Rome (see below). The question of who holds St. Peter's keys is answered by Christ's word and the Church's tradition, not by which side behaved worse in 1204. (Full case: Is the Papacy in the Bible?)
4. Christ condemns the sword raised against brothers
Catholics read Christ's words as a judgment on 1204: "Put your sword back into its sheath, for all who take the sword will perish by the sword" (Matthew 26:52). He commands us, "love your enemies, and pray for those who persecute you" (Matthew 5:44). The crusaders who attacked fellow Christians did the opposite. That is why the Catholic Church condemns what they did, rather than defending it.
5. Reconciliation is a command, not an option
"Therefore, 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, and then come and offer your gift" (Matthew 5:23–24). The Orthodox brother has something against the Latin. Christ's command applies to both: the Latin must repent, and both must seek the unity Christ prayed for, "that the world may believe that you sent me" (John 17:21).
Objections Answered
(a) "1204 shows what papal supremacy really is."
At its strongest: Rome claimed jurisdiction over all Christians; Latin knights then conquered the capital of Eastern Christianity, and "A Latin, Thomas Morosini, was named Patriarch of Constantinople" (OCA). Papal supremacy, the argument goes, was always about domination, and 1204 was its logical end.
Answer: The pope did not command the sack. He forbade the attack on Zara, protested the march on Constantinople, and condemned the sack in the strongest words. A pope who writes that the Greeks detest the Latins "with reason" is not celebrating domination. More importantly, Christ Himself forbade His apostles to rule like pagan kings (Luke 22:25–26), and the abuse of an office never disproves the office. Byzantine emperors exiled patriarchs, St. John Chrysostom among them; no Orthodox believer concludes that the patriarchate is therefore false. The question is what Christ gave St. Peter, and that is answered by Matthew 16, Luke 22, and John 21, not by Venetian galleys.
(b) "After 1204, reunion was impossible. Lyons and Florence prove it."
At its strongest: The OCA says 1204 raised animosity so high that later reconciliation efforts "had virtually no chance." The unions of Lyons (1274) and Florence (1439) were rejected by the Orthodox faithful.
Answer: It is true that those unions did not last, and the memory of 1204 is part of the reason. But notice what that concedes: the obstacle was a wound of memory, not a new doctrine. Memories can be healed. That is exactly what has been happening since 1965, when Pope St. Paul VI and Patriarch Athenagoras I declared that they "regret and remove both from memory and from the midst of the Church the sentences of excommunication which followed these events" and "commit these excommunications to oblivion" (Joint Catholic-Orthodox Declaration). "Impossible" is not a word Christians may use about a prayer of Christ.
(c) "An apology is not enough. Rome must give up its claims."
At its strongest: Apologies for 1204 are welcome, but if the papal claims caused the schism, only renouncing them can end it.
Answer: The Catholic Church can repent of sins. She cannot renounce a gift of Christ, because it is not hers to renounce. The 1965 declaration itself was honest: the gesture of pardon "is not sufficient to end both old and more recent differences." The goal it named was a return to "that full communion of faith, fraternal accord and sacramental life which existed among them during the first thousand years of the life of the Church." In that first millennium, Eastern Fathers and councils spoke of Rome in terms that are hard to reduce to a primacy of honor alone (see below). Returning to the first millennium means returning to St. Peter's see, not away from it. (See Was the Pope's Primacy Recognized in the First Millennium?)
(d) "If the Catholic Church were the true Church, her members would not have done this."
At its strongest: Christ said a tree is known by its fruit. A Church whose soldiers sacked the holiest city of the East cannot be the Church of Christ.
Answer: By that test, no Church survives, since every Christian body has members who committed great sins. Christ Himself said the weeds and wheat would "grow together until harvest" (Matthew 13:30). The Church is holy because Christ is holy, and her members are sinners being healed. The Catholic Church's response to 1204, condemnation by the reigning pope and sorrow and a plea for forgiveness from his successor eight centuries later, is itself the fruit of a Church that knows she is accountable to Christ.
The Early Church Agrees
The Fathers of the undivided Church, whom Catholics and Orthodox both venerate, knew that schism is a grave evil and looked to Rome as the center of unity.
- St. Ignatius of Antioch (Letter to the Romans, salutation, c. AD 110), an Eastern bishop, greets the Roman Church as the one "which also presides in the place of the region of the Romans" and "which presides over love" (newadvent.org).
- St. Irenaeus of Lyons (Against Heresies 3.3.2, c. AD 180), raised in Asia Minor: "For it is a matter of necessity that every Church should agree with this Church, on account of its preeminent authority [potiorem principalitatem]" (newadvent.org). And on schism (4.33.7): those "who give rise to schisms" "cut in pieces and divide the great and glorious body of Christ," and "no reformation of so great importance can be effected by them, as will compensate for the mischief arising from their schism" (newadvent.org).
- St. Cyprian of Carthage (Epistle 54 14, c. AD 252): schismatics sailed "to the throne of Peter, and to the chief church whence priestly unity takes its source" (newadvent.org).
- St. John Chrysostom (Homily 11 on Ephesians, late 4th century): "Nothing so provokes God's anger as the division of the Church" (newadvent.org).
- Council of Chalcedon (AD 451, Session II), its bishops almost all Eastern, after hearing Pope St. Leo the Great's Tome: "Peter has spoken thus through Leo. So taught the Apostles" (newadvent.org).
These words were written long before any crusade. They show that Eastern as well as Western witnesses looked to Rome as the center of unity. The sins of 1204 belong to the Latins who committed them; the witness of the Fathers belongs to us all.
Conclusion
The Fourth Crusade did not cause the schism, but it poured salt into a wound already centuries deep, and the Catholic Church has never denied it. A pope condemned the sack within months; a pope, eight centuries later, expressed deep regret for it and begged forgiveness for Catholics' sins against the Orthodox. That is the honest record. But repentance for sin is not the surrender of truth. The question that divided East and West before 1204 is the question that still divides us: what did Christ give St. Peter when He gave him the keys and told him to strengthen his brothers? Scripture and the Fathers, Eastern and Western, point to the answer the Catholic Church gives.
The healing has begun. In 1965 the excommunications were committed "to oblivion." In 2004 a pope and a patriarch prayed that "the Lord of history will purify our memory of all prejudice and resentment and obtain for us that we may advance in freedom on the path to unity." The path is open. Christ is still praying "that they may all be one" (John 17:21). (See also What Is the Difference Between Catholic and Orthodox?)
Come home. The sins of 1204 were real, but they did not move St. Peter's chair, and the unity Christ prayed for is still offered 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
Did the pope order the sack of Constantinople? No. Pope Innocent III had forbidden the crusaders' earlier attack on Christian Zara and protested their march on Constantinople, and when he heard of the sack he condemned it, writing that the crusaders' swords were "now dripping with Christian blood."
Has the Catholic Church apologized for 1204? Yes. Pope St. John Paul II expressed "deep regret" in Athens in 2001 and asked "the forgiveness we beg of him," and in 2004 he shared "the same indignation and sorrow that Pope Innocent III expressed."
Were the excommunications of 1054 lifted? Yes. On December 7, 1965, Pope St. Paul VI and Patriarch Athenagoras I committed them "to oblivion," while acknowledging that this "is not sufficient to end both old and more recent differences." Full communion has not yet been restored.
Sources
Scripture (NABRE, bible.usccb.org): Matthew 5:23–24, 44; Matthew 13:30; Matthew 16:18–19; Matthew 26:52; Luke 22:25–26, 31–32; John 17:20–21; John 21:17; Romans 3:3–4.
Catechism of the Catholic Church (vatican.va): 817, 819, 820, 838; 882.
Church documents: Pope Innocent III, letter to Cardinal Peter of St. Marcellus ("Given July 12"), trans. J. Brundage (Internet Medieval Sourcebook); 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); Pope St. John Paul II, Welcome Address to Ecumenical Patriarch Bartholomew I (June 29, 2004).
Church Fathers and councils (newadvent.org): Ignatius of Antioch, Letter to the Romans; Irenaeus, Against Heresies 3.3.2 and 4.33.7; Cyprian, Epistle 54 14; John Chrysostom, Homily 11 on Ephesians; Council of Chalcedon (451), Session II.
Orthodox sources (oca.org): The Orthodox Faith, vol. 3, "The Fourth Crusade"; The Orthodox Faith, vol. 3, "The Great Schism".
History: Britannica, "Fourth Crusade"; Britannica, "Siege of Zara"; Catholic Encyclopedia, "Crusades"; Catholic Encyclopedia, "Pope Innocent III".