How did the Catholic and Eastern Orthodox churches split?

The Roman Catholic Church and the Eastern Orthodox Church broke communion during the East-West Schism of 1054, following a gradual process of estrangement driven by historical, linguistic, and theological differences. In recent decades, ecumenical efforts and dialogues of charity have warmed relations, culminating in the lifting of mutual excommunications in 1965.

What we know

• The Catholic Church and the Eastern Orthodox Church broke communion during the East-West Schism of 1054. [2]
• The main theological differences between the two churches involve papal primacy and the filioque clause. [3]
• Pope Paul VI and Ecumenical Patriarch Athenagoras I jointly lifted the mutual excommunications of 1054 in 1965. [2]
• The Second Vatican Council ushered in a new era of relations, with the Roman Church describing the Orthodox as separated brethren with valid sacraments and an apostolic priesthood. [2]

Where to go next

• what caused itWhat caused the East-West Schism?
• how it workedWhat are the main theological differences?
• whenWhat happened at the Second Vatican Council?
• what followedHow did the Fall of Constantinople affect Orthodoxy?
• the bigger pictureWhat is the history of the Eastern Orthodox Church?
• an unexpected connectionWhy is reunification seen as inevitable by some church leaders?Despite centuries of official schism and theological disputes, modern patriarchs like Bartholomew I have expressed the view that healing the divide is inevitable.

Sources

• [1]Catholic–Eastern Orthodox relations (Wikidata Q85751011) · CC0 1.0
• [2]Catholic–Eastern Orthodox relations · CC BY-SA 4.0
• [3]Theological differences between the Catholic Church and the Eastern Orthodox Church · CC BY-SA 4.0
• [4]History of the Eastern Orthodox Church · CC BY-SA 4.0
• [5]Ecclesiastical differences between the Catholic Church and the Eastern Orthodox Church · CC BY-SA 4.0