This was done during the Great Schism in which the Eastern and Western Churches excommunicated each other.
The Great Eastern Schism in 1054. The pope and the patriarch mutually excommunicated each other.
No, Pope Leo IX was not excommunicated from the Roman Catholic Church; he was the pope from 1049 to 1054. However, he is notable for his role in the East-West Schism. In 1054, he excommunicated Patriarch Michael I Cerularius of Constantinople, which contributed to the formal split between the Roman Catholic and Eastern Orthodox Churches. Leo IX died shortly after the excommunication, and he remained recognized as a legitimate pope.
The Great Schism occurred in the year 1054 and was when the Catholic Church and the Orthodox Church parted ways. It was a situation that had been brewing for many years because of both theological and political differences. It came to a head in 1054 when the Pope in Rome and the Patriarch of the East in Constantinople mutually excommunicated each other.
Pope Benedict IX
Pope Leo IX excommunicated Patriarch Michael Cerularius of Constantinople, who, in turn, excommunicated Pope Leo in 1054 AD. This was caused because of disagreements over the unauthorized changes made by Pope Leo to the Nicene Creed (by adding the "Filioque clause"). The Orthodox Church maintains that Holy Spirit "proceeds from the Father alone, whereas the Roman Catholics claimed that the Holy Spirit proceeds from the Father "and the Son" which goes against the Bible. "The Bible states that ...the Spirit of truth who proceeds from the Father..." (John 15:26). However, both of these excommunications were mutually removed in 1965 by Pope Paul VI and Patriarch Athenagoras I.
the Western and Eastern churches excommunicated each other
The Western and Eastern Churches excommunicated each other.
They formally split the Christian Church apart They created two completely separate churches.
In 1054 AD the leaders of each Church mutually excommunicated each other.
Following the Great Schism of 1054, the patriarch of Constantinople and the pope of Rome excommunicated each other, formalizing the split between the Eastern Orthodox and Roman Catholic Churches. The patriarch, Michael I Cerularius, closed Latin churches in Constantinople and rejected papal authority, while Pope Leo IX sent a legation to negotiate but ultimately supported the excommunication. This mutual condemnation solidified the theological and political divisions that had been developing over centuries. The schism was further entrenched by cultural, linguistic, and liturgical differences between the two branches of Christianity.
The Churches that came out of the Great Schism of 1054 both claimed to be the original Christian Church. One was the Roman Catholic Church and the other was the Orthodox Church, although this is a more general term for a group of Churches with more than one Patriarch.
Roman Catholic AnswerThe Eastern Schism was centuries in the making but became fixed in 1054, when the Patriarch of Constantinople, Michael Cerularius was excommunicated by the papal legates for opposing the use of leavened bread by the Latin Church and removing the Pope's name from the diptychs to be prayed for in the Eucharistic liturgy. from Modern Catholic Dictionary by John A. Hardon, S.J. Doubleday & Co., Inc. Garden City, NY 1980