Who started the Great Schism, the split between the present day Orthodox and Roman Catholic churches? This seems like a question that can only be answered with years of research and pouring over many books. Here, we endeavor upon a concise answer, one which is not shallow, but truly gets to the heart of the matter.

How can we do this? First, we must understand what the Church is. After all, the historical question of who started the schism is not merely pedantic, but it contains certain theological presuppositions relevant to the religious body it pertains to. Only after this question is answered can one determine what schism in the Church is and then how the great schism formed.

Chapter 1 – What is ‘the Church’?

The Church views itself according to the Constantinopolitan Creed as “one, holy, Catholic, and apostolic” Other early Church authorities, like Saint Gregory the Great, sometimes call the Body of Christ the “Orthodox Church:”. He says:

For, though the whole earth was filled with observance of the true faith by the preaching and doctrine of the apostles, yet the Orthodox Church of Christ, having been founded by apostolic institution and most firmly established by the faithful fathers, is further built up through the teaching of divine discourses…To it did all the most blessed apostles, endowed with an equal participation of dignity and authority, convert hosts of peoples. (Registrum Epistolarum, Letter 16, Paragraph 2)

The Patristic consensus, something that pertains to the agreement of all of the saints of the Church, is that the Church was begun by Jesus Christ with the ordination of the Apostles to the title of Bishop, through Saint Peter. Though these Apostles had “equal…dignity and authority,” Church tradition teaches that Peter literally ordained the other Apostles to their Bishoprics (Sources: Matt 16:18; Optatus Against the Donatists, Book 1, Chap 10; Eusebius Ecclesiastical History Book 2, Chap 1, Par 2-3; John of Thessalonica, Dormition Homily, Chap 13). To quote John of Thessalonica’s apocryphal account of a conversation between Saint Peter and the other Apostles:

Peter picked up a palm branch and said to John, “You are the virgin [Apostle], it is your duty to sing hymns before the bier, holding this.” Then John said to him, “You are our father and bishop; it is your duty to be before the bier until we bring it to the place [of burial].”

In this way, every Bishopric is Petrine and ultimately sourced in Jesus Christ Himself. (cf Pope Gregory II, “[T]he blessed apostle Peter was the origin of both the apostleship and the episcopate” in MGH, Epistolae 3: 275-7)

Chapter 2 – What is ‘Schism’?

In the early Church, it was understood that all Bishops succeeding from the Apostles were part of this Church provided they did not pack up their bags and leave. The Fathers, who are those saints from whom the Patristic consensus is derived, are unanimous when defining schism that it is the act of both cutting oneself off from communion and setting up a parallel jurisdiction/church where the Church already is. (Sources: St Cyprian, Treatise 1, Par 12, 23 and Epistle 35, Par 9; St Optatus, Against the Donatists, Book I, Chap 10 and Book II, Chap 2; Council of Constantinople I, Canon 1; Augustine, Letter 43, Par 8 and Letter 87, Par 1-2; St Beatus of Liebana on Rev 2:9–cf First-Second Council, Canon 15: Pseudo(?) Pseudo-Isidore of Seville, Epistle 8, PL 83:908)

In Catholic theology, the theology that both sides of the Great Schism ascribe to, it is necessary to follow the consensus of the fathers and uphold the “faith which has been believed everywhere, always, by all. For that is truly and in the strictest sense Catholic,” according to Saint Vincent de Lerins. (Source: Commonitorium Par 6) In the words of Saint Pope Celestine, quoted by Vincent in support of the beforestated rule: “Let novelty cease to assail antiquity.” (Commonitorium, Par 85) For the Catholic, one’s definition of schism must be how the fathers defined it, otherwise it is definitionally un-Catholic.

When determining who started the Great Schism, the contemporary criterion of Catholicity may seem quaint, but it is important to understand as it would be meaningless to discern who started a Church-specific problem between Catholics by the name of “schism” using standards that were not accepted by both sides. And so, discerning Catholicity via patristic consensus is not an arcane theological presupposition which is only relevant to theologians, but it is the only historically legitimate way to answer the question.

And so, many people who follow current events often do not understand the preceding, so they confuse local breaks in communion as equivalent to a categorical schism as typified by the Great Schism. Such local schisms, where there is a break between two individual churches, yet while these churches were often in communion with other churches who were not in schism with either side, was fairly common in the early Church. The Easter controversy, Meletian Schism, and the Constantinople-Rome schism during the 11th century did not break communion categorically between all the churches. In the latter case, Alexandrine communion with Rome persisted until the 13th century. The fathers never confused such local breaks in communion with what they considered as “schism.” (Sources: Council of Carthage 419, Canons 10, 67, 101; Apostolic Canons 10, 11, 31, 32; Council of Antioch 341, Canons 2, 5)

This is because schism had a predictable historical pattern. All of the notorious schismatics the fathers were writing against, such as Novatian (a counter-Bishop of Rome) and Donatus (a counter-Bishop of Carthage) not only went into schism in their local cities, but they spread their schism by ordaining Bishops in parts of the Church that have not left the fold. For example, the Novatians ordained Bishops to replace those who did not recognize the legitimacy of his bishopric throughout the Roman Empire. The Donatists ordained parallel bishops throughout North Africa and even in Rome itself after a dispute broke out over Caecilian of Carthage’s ordination to the Bishopric. In the words of St Augustine the Donatists should have warned themselves:

The great scandal of schism within the Church…may arise and we may be found presuming to set up another altar, not against Caecilianus [of Carthage only], but against the universal Church, which…would still hold communion with him.

Why did the early Church consider this particularly grievous? In the early second century, Saint Ignatius of Antioch wrote, “Wherever the bishop shall appear, there let the multitude also be; even as, wherever Jesus Christ is, there is the Catholic Church.” (Smyrnaeans, Chap 8) Hence, to install a schismatic bishop where a bishop already “appears” was understood to be definitionally un-Catholic because it in effect cut one off from all the other Christian believers within the one “Body of Christ.” (cf Rom 12:4-5, Col 1:18) To quote Saint Paul :

For as the body is one, and has many members, and all the members of the body, being many, are one body; so also is Christ. (1 Cor 12:12)

These may sound like theologically loaded terms, but the consensus pertaining to this theology informed how the early Church operated and understood schism.

Let’s use a historical case study that demonstrates the preceding theology at work. In the fourth century, Saint Meletius, the Bishop of Antioch, was sent into exile during the Arian controversy. Lucifer Cagliari of Sardinia single-handedly (Source: Socrates Ecclesiastical History, Book 3, Chap 6) ordained Paulinus II as Bishop of Antioch. This is considered “uncanonical” or “illegal” within ecclesiastical law, something that is documented to have existed since at least the third century. In any event, Alexandria and Rome recognized Paulinus in place of Meletius and so Meletius did not commemorate them. This is known today as the Meletian Schism.

After the death of Meletius, Saint Flavian was ordained to replace him and was recognized by the Council of Constantinople I, the largest representative body of the Church’s views during its day. Saint Pope Damasus I (and then Saint Pope Siricius) and other Italian Bishops did not recognize Flavian, even though Saint Theophilus of Alexandria and even bishops in Illyricum (who were under Roman jurisdiction) later did. (Sources: Theodoret, Ecclesiastical History, Book 5, Chapter 23; Council of Constantinople (394) Under Nectarius of Constantinople and Theophilus of Alexandria) This vindicates Meletius and Flavian, who are recognized by both Roman Catholics and Orthodox as saints—and not Paulinus, Evagrius, and other Paulinian successors.

Sometime in the late 390s, Rome finally re-entered into communion with the canonical Church of Antioch. The preceding episode illustrates how a schism began (Rome and Alexandria did not recognize Meletius) and how it was ultimately consummated (Rome and Alexandria entered communion with the parallel Bishopric in Antioch). The schism was only healed by re-entering into communion with the canonical Church of Antioch and ceasing recognition of the parallel jurisdiction. This historical example is especially important as the authority of an Ecumenical (or “Church-wide”) Council and the veneration of saints which both sides, Roman Catholic and Orthodox, accept delineates the correct and incorrect parties in this matter according to the standards applicable to each side.

Chapter 3 – Historic Ecclesial Hierarchy

Before answering the question of “who started the Great Schism” it is also important to discuss how the early Church understood episcopal hierarchy and “jurisdictional boundaries.” The ancient Church has always been organized around a local Bishop, with each local church having oftentimes one or more bishops. (Sources: Phil 1:1; 1 Clem 1, 42, and 44; 47; Ignatius, Smyrnaeans, Chap 8) As early as the first century, one can surmise that some Bishops, like Saint Titus, were set above other Bishops over a certain geography, such as those in Crete. (Source: Titus 1:5) While implications of hierarchy within the episcopacy can be inferred from Saint Irenaeus’ writings, they are made explicit during the third century. For example, Saint Dionysius of Alexandria wrote in a dispute with Pope Saint Stephen I:

Moreover in judging of and dealing with particular cases…we give instructions to the local primates who under divine imposition of hands were appointed to discharge these duties; for they shall give a summary account to the Lord of whatsoever they do. (Dionysius to Stephen, Letter I)

As one can see, the Bishop of Alexandria “gives instructions to the local primates.” This presupposes a hierarchical superiority within specific, geographic, jurisdictional boundaries. 

Apostolic Canon 34, which was likely dated to the second or third century (Source: John Henry Newman, Primitive Christianity, Volume 4, p. 430), also speaks of a hierarchy between Bishops within a given geography:

The bishops of every nation must acknowledge him who is first among them and account him as their head, and do nothing of consequence without his consent…But neither let him (who is the first) do anything without the consent of all; for so there will be unanimity, and God will be glorified through the Lord in the Holy Spirit. (Apostolic Canon 34/35)

It should not be a surprise that before Christianity was officially tolerated by Saint Constantine and made the state religion by Saint Theodosius, Bishops were organized among provincial lines within the Roman Empire, with a hierarchical structure that corresponded generally with the precedence a certain city and/or province had within the Empire. (Sources: Letter of the Council of Nicea to the Egyptian Church, Par 1; Emperor Constantine to All Church Concerning the Date of Easter, Par 10) This had practical implications, but it is hardly a spiritual criterium. Theologically, the location of an Apostle’s relics within a given city played the largest role in justifying its importance. (Source: Irenaeus, Against Heresies, Book III, Chap 3, Par 2) This theological criterium did not always outweigh practical considerations, as Jerusalem for the first few centuries had their Bishopric in Aelia (Source: Eusebius, Church History, Book I, Chap 6, Par 4) and Constantinople’s founding saint, Andrew, was martyred in a whole other city. Later church canons as propagated by Ecumenical Councils, such as Canon 3 of Constantinople I and Canon 28 of Chalcedon, explicitly invoked the practical criterium when delineating church jurisdiction. The theological criterium was never canonized.

Where did these church jurisdictions come from so that their boundaries can be subject to future disputes? It may be difficult to picture this in one’s mind, but few appreciate that due to most churches being traditionally started and administered by Saints Peter and Paul, theologically, this would mean that due to their relics being in Rome the Roman Bishop would be “first among” these churches. Additionally, this would give Rome, geographically, by far the largest jurisdiction in the ancient Church as Saint Paul was the most successful evangelizer in Church History. Nevertheless, tradition and correspondence between Bishops demonstrates that jurisdictions in North Africa (centered around Carthage), Egypt (centered around Alexandria), and the Middle East (centered around Antioch) functioned independently with the consent of all, including Rome. (Sources: Dionysius’ Letters to Pope Stephen and Sixtus II; Council of Carthage 256 “On Rebaptism”, Par 1; Eusebius, Church History, Book VII, Chap 30, Par 17, cf. Par 19) 

In the event where jurisdiction over a locality was disputed, such as Rome’s alleged local jurisdiction over Ephesus during the second century Easter Controversy, matters were solved through discerning a Churchwide consensus. In the background of this controversy was the fact that Ephesus arguably was a “Pauline” city as it was started by Saint Paul’s missionary work. Theoretically, this would make Ephesus under Roman jurisdiction. However, tradition in Ephesus taught that the city was the last known whereabouts of Saint John, making the city Johnnanine and the head of all Johannine churches, thereby independent of Rome. (Source: Eusebius, Church History, Book V, Chapter 24, Par 2) 

As stated previously, from the beginning of Church History there was a hierarchy between bishops which was geographically based, and the means of resolving jurisdictional disputes was through appeals to the world’s churches so there would be a common consent among Christians. Eusebius records that local churches throughout the world weighed in on the question, in his words “sharply rebuking” the Bishop of Rome for his “attempt” to excommunicate churches in Asia Minor, (Source: Ibid., Par 10) as one cannot actually excommunicate someone when it is not in his power to do so. Local synods throughout Christendom addressed the Pope’s excommunication dismissively despite their agreement with Rome over the date of Easter, as their consent to resolving what was viewed as an inter, as opposed to intra, Church dispute was considered necessary. The same regional approach to Churchwide resolution of disputes in lieu of an Ecumenical Council happened several times during the third century in response to controversies pertaining to Novationism, rebaptism, and Paul of Samosata’s deposition.

Chapter 4 – Precipitation of the Great Schism

After the Ecumenical Council of Nicea in the early fourth century, politically and socially, the Mediterranean world was changing considerably as the borders of the Roman Empire were in flux. The Sassanid Empire largely subjugated the Church within their borders after the Council of Seleucia-Ctesiphon and this later formalized into a schism. The Arab Caliphate likewise did the same among religious sectarians in the Near East and Egypt. In any event, the regional borders of Roman jurisdiction, intact in the Balkans and southern Italy since the missionary work of Saint Paul, generally did not change. 

However, a cultural estrangement between east and west began to set in. The speaking of Latin in the east continually declined, with Latin no longer being recognized as the language of Byzantine government during the reign of Heraclius in the 7th century. Yet Rome, which had been under Byzantine occupation since the 6th century, largely had Greek Popes until the mid 8th century. Greek was used by many, some allege most, Roman clergy during this period. (Source: Ekonomou, Byzantine Rome and the Greek Popes, p. 245) 

Byzantine occupation was generally not friendly as Popes were regularly intimidated and arrested, sometimes martyred such as Saint Pope Martin I. Usually, some theological heresy served as a pretext for the worst abuses. During Byzantium’s descent into iconoclasm, a religious policy intolerant of the veneration of icons, historically Roman territories in the Balkans and southern Italy were “legally” seized and transferred to Constantinople’s jurisdiction. This was possible because in the late 7th century, the majority of churches accepted the 38th canon of the Council of Trullo:

If any city be renewed by imperial authority, or shall have been renewed, let the order of things ecclesiastical follow the civil and public models. (cf Canon 17 of Chalcedon)

In other words, imperial authority can change ecclesiastical boundaries to “follow the civil and public models.” Due to the Byzantine Empire having authority in the Balkans and Southern Italy, the transfer was deemed canonically legitimate.

When the Lombards successfully wrestled Northern Italy from Byzantine hands in 751, Byzantium’s ability to control Rome disappeared as Rome sought Frankish protection from the Lombards. Adding to this estrangement was the fact that after this the Popes were no longer Greek and the Franks encouraged an independent, anti-Byzantine posturing. 

In any event, Rome up to this point had accepted the canons of Trullo. In the words of Alexander Bogolepov:

Pope Hadrian wrote: ‘All the Six Holy Councils I receive, with all the canons which were rightly and divinely promulgated by them,’ and as an example of these canons, he referred to canon 82 of the Trullan Council, concerning the depicting of Christ as a lamb. Therefore when the Seventh Ecumenical Council, with the consent of the Papal legates, recognized the canons of the Six Ecumenical Councils, this meant that the Trullan Council was also recognized among them. (Source: Alexander A. Bogolepov, Which Councils Are Recognized As Ecumenical?, St. Vladimir’s Seminary Quarterly, 1963, Volume 7, Number 2, p. 68) 

However, there was undoubtedly a difference in interpretation as Rome continually requested the restoration of Roman jurisdiction, until Pope John VIII dropped these requests and recognized Constantinopolitan jurisdiction in these lands in exchange for a military alliance against the Saracens. (Source: Fred E. Engreen, Pope John the Eight and the Arabs, Speculum, No. 20, No. 3, p. 323-324) In any event, no schism began over the issue of jurisdictional changes as they were affirmed in canon law and consented to by all parties involved.

Amidst these territorial considerations, serious doctrinal changes were afoot and the western churches began adopting the Filioque in their “Creed.” The “Creed,” a reference to the Constantinopolitan Creed, was understood to be a necessary confession of the Christian faith and regulative of popular belief. Changing it was tantamount to forswearing the common faith of the Church. Yet, this change was something that initially did not create a schism as it was understood in the West, according to Saint Maximus, that the Filioque did not contradict the universal belief that the Father was the sole eternal cause of the Spirit. (Source: Maximus, Letter to Marinus) As time persisted, it became clear that many western Bishops no longer believed this, as evidenced by the infighting between Pope Adrian I and the Frankish theologians exactly on this point at the turn on the 8th century. (Source: Reverend John Mendham, Seventh Ecumenical Council, p. 90-91)

By the next century, this escalated into a break in communion between Constantinople and Rome amidst political squabbles. The break was only healed when Pope John VIII, as verified in multiple letters of his in both Latin and Greek (a fact that demonstrates these letters are not forgeries), affirmed the reunion Council of Constantinople in 879-880 and recognized only the Creed without the Filioque as required by that Council in multiple letters, one being to Photius, the Bishop of Constantinople. (Source: Bogolepov, Which Councils Are Recognized As Ecumenical?, p. 65) The earliest Latin canonists such as Ivo of Chartes (11th century) and Gratian (12th century) likewise “considered the Photian synod of 879-880 to have been duly approved by Pope John VIII,” citing Latin letters to this effect. (Source: Daniel J. Castellano, Arcane Knowledge [Roman Catholic blog]) Only later did western historians and canonists, in opposition to all extant primary sources, change their estimation of the course of events.

While the 879-880 council appeared to disallow Latin Christians from using the Filioque, it was obviously not interpreted this way by western churches as outside of John VIII the council had little support in the West. (Source: Bogolepov, Which Councils Are Recognized As Ecumenical?, p. 65) Nevertheless, Rome itself abided by the agreement as they had not changed the Creed up to that point. To quote Pope Leo III, who wrote during the turn of the 8th century, “it [the Filioque] may be sung in teaching, and be taught by being sung: but neither by writing nor by singing may it be unlawfully inserted into that, which it is forbidden us to touch.” (Source: A. Brown, A Harmony of Anglican Doctrine with the Doctrine of the Catholic and Apostolic Church of the East, p. 138) Latin theology had accepted the existence of the Filioque and allowed it to “be taught by being sung,” but they officially did not put it in the Creed.

In the Council of Constantinople, the Roman and Eastern churches made a truce which had maintained the status quo preceding the break in communion. Eastern Bishops believed they had prevented the Filioque from being expounded. Rome admitted that on an official level the East was correct, but the council did not specifically enough condemn their peculiar doctrine.

Chapter 5 – The Author of Schism

When discerning the issue of schism, the obvious question is who broke the truce and whether what they did after the truce was broken fits the definition of schism discussed before. Using these criteria, scholarship and partisans on both sides of this issue agree that the Western faction of the Church is to blame on both counts.

In the early 11th century, the Roman church unilaterally changed the Creed—something the truce disallowed for. Then, they excommunicated Constantinople for allegedly “removing [the] filioque from the original Creed” amongst other things. (Source: Brett Whalen, Rethinking the Schism of 1054, Traditio, Vol. 62, p. 17, Footnote 60) This allegation is historically inaccurate, and it demonstrates which side started a fight in violation of an earlier truce.

At the same time, the Normans conquered Byzantine Italy and with the assent of Rome, replaced its Constantinopolitan bishops, introducing a parallel Latin bishopric alongside Greek bishops who served southern Italy’s Greek population. (Source: Paul Stephenson, The Byzantine World, p. 121). They also imposed Latinization, including the imposition of the Filioque. This was both heretical and schismatic, as it propagated the Germanic, as opposed to the traditional Latin view of that doctrine. 

It can legitimately be argued that Italian Christians largely consented to their new episcopacy and so this muddies the waters as to this being the origin of the Great Schism. However, the Western side was decisive in exacerbating matters during the Crusades which followed soon thereafter. Western Christians, with Papal support, repeatedly installed parallel bishops and enforced liturgical changes including the Creed sometimes in locales they had not even conquered. This includes setting up parallel churches in:

  • Jerusalem and Antioch (12th century). 
  • The Aegeans and Constantinople (13th century). 
  • Alexandria (13th cenutry)
  • Baltic, Balkan, Russian, Ukrainian, and Greek lands (13th to 17th centuries).

In effect, the Papacy through their ordinations and expounding of the Filioque created another church in places there were already Bishops who had belonged to the one, holy, Catholic (as St Vincent defined it), and apostolic Church. They likewise had different doctrines to that same Church. The Roman church had clearly consummated a schism, becoming a new, independent Christian body. They did so with the use of force.

Contrarily, the eastern churches never ordained bishops in a Roman Catholic land until the 19th century or took part in any forced conversions of Roman Catholic laity until forced to by Stalinist persecution in the 1940s—a point so far after the schism that one cannot accuse them of creating a parallel bishopric within the same Church. Hence, while one can disapprove of the preceding, definitionally they would not meet the criteria for schism. 


And so, if one seeks to answer historically “who caused the Great Schism” according to the criteria of the actual members of the Church where the schism occurred, it must be discerned that the Roman church is to blame. They changed their doctrine of the Filioque, broke a truce not to add it to the Creed, excommunicated eastern Christians over this doctrine amongst others, and ultimately attempted replacing eastern bishops without their consent—making a second church. Religious divisions as the result of Papal policy since the crusades have significantly shaped history and persist to this day.