On July 16, 1054, Patriarch of Constantinople Michael Cerularius wasexcommunicated from the Christian church based in Rome, Italy. Cerularius’s excommunicationwas a breaking point in long-rising tensions between the Roman church based in Rome and the Byzantine church based in Constantinople (now called Istanbul). The resulting split divided the European Christian church into two major branches: the Western Roman Catholic Church and the Eastern Orthodox Church. This split is known as the GreatSchism, or sometimes the “East-West
Schism
” or the “
Schism
of 1054.”
The Great
Schism
came about due to a complex mix of religious disagreementsandpoliticalconflicts. One of the many religious disagreements between the western (Roman) and eastern (Byzantine) branches of the church had to do with whether or not it was acceptable to useunleavenedbread for thesacramentofcommunion. (The west supported the practice, while the east did not.) Other objects of religious dispute include the exact wording of the Nicene Creed and the Western belief that clerics should remain celibate.
These religious disagreements were made worse by a variety of political
conflicts
, particularly regarding the power of Rome. Rome believed that the pope—the religious leader of the western church—should have authority over the
patriarch
—the religious
authority
of the eastern church. Constantinople disagreed. Each church recognized their own leaders, and when the western church eventually
excommunicated
Michael Cerularius and the entire eastern church. The eastern church retaliated by excommunicating the Roman
pope
Leo III and the Roman church with him.
While the two churches have never reunited, over a thousand years after their split, the western and eastern branches of Christianity came to more peaceable terms. In 1965,
Pope
Paul VI and
Patriarch
Athenagoras I lifted the longstanding mutual excommunication decrees made by their respective churches.
Today, the two branches of
Christianity
remain distinct expressions of a similar faith. Roman
Catholicism
is the single largest Christiandenomination, with more than a billion followers around the world.
Eastern Orthodoxy
is the second-largest Christian
denomination
, with more than 260 million followers.
Eastern Orthodoxy
includes national churches, such as the Greek Orthodox Church and Russian Orthodox Church.
