Final answer:
The Eastern Orthodox Church and the Roman Catholic Church were the two halves of Christianity after the Great Schism in 1054, with the former being Eastern and the latter Western.
Step-by-step explanation:
The Eastern Orthodox Church was the Eastern half of the Christian church and the Roman Catholic Church was the Western half of the Christian church after the Great Schism. This historical event took place in 1054, leading to significant religious, cultural, and geographical distinctions between the two branches of Christianity. The Eastern Orthodox Church, which utilized Greek and allowed married clergy, became centered in the Byzantine capital of Constantinople, whereas the Roman Catholic Church, using Latin and mandating clerical celibacy, remained under the pope's authority in Rome. Over time, the Roman Catholic Church further split during the Protestant Reformation initiated by figures like Martin Luther in the 14th century. Nevertheless, the initial division into Eastern Orthodox and Roman Catholic branches remains one of the most significant splits in Christian history.