The East–West Schism of 1054: Causes and Consequences

Before the these tense moments in the 11th century AD, Christians belonged to one church that began under the Roman Empire.

However, over centuries, two main centres of power had begun to form: Rome in the West, where people spoke Latin, and Constantinople in the East, where people spoke Greek.

Each one had its own leading bishop. In the East, the church believed that there were five main regions, known as 'sees', of equal importance with one another.

These were Constantinople, Alexandria, Antioch, Jerusalem and Rome.

Meanwhile, the Western church treated the pope at Rome as its leader. Rome’s claim to rule all churches had never been accepted in the East.

However, earlier disputes, such as the 8th-century debate over church images, had already started to widen this gap. 

In fact, over the preceeding centuries, a number of unresolved problems had only contributed to the misunderstandings between the two sides.

While each one might seem quite minor to the modern mind, they were incredibly important to the church leaders on both parties.

The Western church had added the words "and the Son" to the Nicene Creed which had been created in the 4th century AD without consulting with other sees.

This Latin phrase said the Holy Spirit came from both the Father and the Son.

Eastern Christians said this went against the original creed and upset the balance of Trinitarian belief.

There were other disagreements, such as using unleavened bread in Western communion and rules on priests marrying or remaining single.

Eastern leaders felt Western leaders had no right to force celibacy on their priests.

Reform movements in the West pressed the pope’s power over all churches. Popes like Leo IX said they had authority in both East and West because their unique authority came from St Peter, who had taught and died in the city of Rome in the 1st century.

However, the Eastern tradition held that the emperor and church councils held final authority, and each church had its own way of governing.

This meant that the West was moving to a strong pope-led system while the East kept a council-based and imperial approach.

The Latin West and Greek East used different languages, church ceremonies and rules.

Western worship was conducted in Latin, had distinctive clothing for the clergy that had been adapted from ancient Roman styles, and even followed a different calendar of special saints days that often clashed with Eastern practice.

Ordinary believers in the ast found some Western customs very hard to accept because it seemed so foreign to them.

This was most problematic when one side claimed control over a territory that had traditionally been under the influence of the other.

For example, in southern Italy, western Norman rulers placed Latin bishops in their church and banned Greek services.

In response the Patriarch of Constantinople, Michael I Cerularius, closed Latin churches in the east in 1052.

The division between East and West essentially developed in the far distant past when a split had been created in the old the Roman Empire in the 3rd and 4th centuries.

At that time, there were two emperors: one in the east and one in the west. When the western Roman empire fell to the Germanic invaders, the remaining emperor in the east considered himself to the best last legitimate emperor.

However, when Pope Leo III crowned Charlemagne as a new kind of emperor in 800 CE, the Byzantines saw this as a direct challenge to their imperial claims.

By the 11th century, the Holy Roman Empire and the Byzantine Empire were direct rivals, with both believing their were the real inheritors of the ancient Roman Empire, and, as such, could make claims to own all of its traditional lands.

Unfortunately, in 1054, the pope had become threatened by the Normans and needed allies.

So, Pope Leo IX sent a legate to the east to seek help against his enemies.

Tensions reached their peak in the spring to summer of 1054. In April 1054, Pope Leo IX’s representative, Cardinal Humbert, Henry of Silva Candida, arrived in Constantinople to meet Patriarch Michael Cerularius.

However, negotiations quickly broke down, on 16 July 1054, during a service in the great cathedral of Hagia Sophia.

Angry with his failure to find a political resolution, Humbert laid a papal bull of excommunication on the altar, which officially anathematising Michael Cerularius, the Patriarch, and his supporters.

Then, a week later, the Patriarch held a synod that excommunicated Humbert and the other papal legates in return.

These mutual excommunications by Rome and Constantinople are usually seen as the moment of formal schism.

Still, at the time, observers did not view this as a permanent split, and both sides continued some contact afterwards. 

Following that event, the Eastern churches, later called the Orthodox churches, and the Western, referred to as the Roman Catholic Church, quickly developed separate traditions.

As petty as the events in 1054 seem to be, a number of subsequent events made any reunion almost impossible.

Perhaps the most damaging occurred in 1204, when Western Crusaders captured and looted Constantinople.

There were some efforts at coming back together, but they all failed to reach any agreement on the growing list of difference.

For instance, Western councils at Lyon 1274 and Florence 1439 agreed to a papal-imposed union, but these were all rejected by the Byzantine side. 

In the end, the split has never fully healed. Today, the two churches remain separate, each with its own leaders, theology, and liturgical traditions.

In 1965, Pope Paul VI and Ecumenical Patriarch Athenagoras officially lifted the old 1054 excommunications as a gesture of goodwill, and modern ecumenical dialogues continue.

But even today, Catholics and Orthodox do not fully share Communion in a way that was common before the Great Schism.