Lesson 11

The Great Schism, which formally divided the Eastern Orthodox Church and the
Western Catholic Church in 1054, was a defining moment in Christian history. At the
heart of this division were key bishops whose actions, decisions, and leadership
shaped the course of events. In this lesson, we will focus on the pivotal roles of the
Patriarch of Constantinople and the Pope in Rome, examining how their leadership
reflected theological, cultural, and political tensions that ultimately led to the rupture.

To understand the significance of these bishops in the Great Schism, it is essential to
recall some of the underlying causes discussed in the previous lesson. Theological
disagreements, such as disputes over the use of unleavened versus leavened bread in
the Eucharist, the inclusion of the Filioque clause in the Nicene Creed, and differing
views on papal authority, created deep divisions. Cultural differences between the Latin
speaking West and the Greek-speaking East compounded these theological issues.

 
Political factors, including the shifting balance of power between the Byzantine Empire
and the emerging European kingdoms, added further complexity. These factors set the
stage for the confrontation between the Patriarch of Constantinople and the Pope in
Rome, each representing their respective traditions and authority.

Let us begin with Michael Cerularius, the Patriarch of Constantinople from 1043 to
1059. Cerularius was a vocal critic of Western practices, particularly those he viewed
as deviations from Orthodox traditions. Among his grievances were the Western
Church’s use of unleavened bread in the Eucharist, its acceptance of clerical celibacy,
and its insistence on the supremacy of the Pope. Cerularius saw these practices as
unacceptable innovations, reflecting what he believed to be a growing divergence
between East and West. His position as Patriarch placed him at the center of
theological debates, making him a key figure in the escalating tensions.

In 1052, Cerularius took a bold step by closing Latin churches in Constantinople,
effectively banning Western liturgical practices in the city. This action was a direct
challenge to the authority of the Pope and the Latin Church, signaling a refusal to
compromise on Orthodox traditions. Cerularius also sent letters to other Eastern
patriarchs, rallying support for his position and reinforcing the idea that the Eastern
Church must remain united against perceived Western encroachments. His leadership
in this period demonstrated both his determination to defend Orthodox practices and
his willingness to confront Rome directly.

On the other side of the divide, Pope Leo IX played an equally critical role. Leo IX, who
served as Pope from 1049 to 1054, was a staunch advocate for the authority of the
papacy. He viewed the Pope as the supreme leader of Christendom, a position that
clashed with the Eastern Church’s view of a more collaborative leadership among the
patriarchs. Leo IX believed in the universal jurisdiction of the Pope, asserting that the
Bishop of Rome held primacy over all other bishops. This fundamental disagreement
over authority was a major point of contention between the two churches.

In response to Cerularius’s actions, Pope Leo IX sent a delegation to Constantinople in
1054, led by Cardinal Humbert of Silva Candida. Humbert carried a letter from the Pope
that outlined the Western Church’s grievances and demanded that Cerularius recognize
the Pope’s authority. However, the tone of the letter was confrontational, further
inflaming tensions. When Humbert arrived in Constantinople, he and Cerularius
engaged in heated debates, with neither side willing to yield. The discussions quickly
deteriorated into accusations and recriminations, reflecting the deep divisions between
the two leaders and their respective churches.

The situation reached its climax on July 16, 1054, when Humbert placed a bull of
excommunication on the altar of Hagia Sophia in Constantinople. This bull declared
Cerularius and his followers excommunicated from the Roman Church, an act that
symbolized the breaking point in relations between East and West. In retaliation,
Cerularius convened a synod that excommunicated Humbert and his delegation,
formalizing the schism. While these excommunications were initially limited to the
individuals involved, they represented the culmination of centuries of growing divisions
and effectively institutionalized the split between the two churches.

It is important to note that neither Cerularius nor Leo IX acted in isolation. Both were
representatives of broader traditions and institutions, carrying the weight of their
respective churches’ histories and beliefs. Their actions during this period reflected the
longstanding tensions between East and West, but they also demonstrated the
personal leadership styles of each bishop. Cerularius’s assertive defense of Orthodox
practices and Leo IX’s uncompromising stance on papal authority highlighted the
challenges of bridging theological and cultural divides.

The roles of these bishops also underscore the importance of communication—or the
lack thereof—in resolving conflicts. Throughout the events leading up to the Great
Schism, attempts at dialogue between East and West were often hampered by
misunderstandings, mistrust, and entrenched positions. The debates between Humbert
and Cerularius exemplified this breakdown in communication. Rather than fostering
mutual understanding, their interactions reinforced existing divisions, making
reconciliation increasingly unlikely.

In conclusion, the Patriarch of Constantinople and the Pope in Rome were central
figures in the Great Schism, both embodying the theological, cultural, and political
tensions of their time. Michael Cerularius’s defense of Eastern traditions and Leo IX’s
assertion of papal supremacy highlighted the profound differences between the two
churches. Their actions, particularly the mutual excommunications of 1054, marked the
formal rupture between the Eastern Orthodox and Western Catholic traditions. While
the schism was not solely caused by these bishops, their leadership during this period
was pivotal in shaping its outcome. Understanding their roles provides valuable insight
into the complexities of church leadership during one of the most transformative
moments in Christian history.