The "Eastern Church" refers to the Christian traditions and communities that developed in the eastern regions of the Roman Empire, particularly in areas like Constantinople, Alexandria, and Antioch. It is primarily represented by the Eastern Orthodox Church, which includes various national churches such as the Greek Orthodox and Russian Orthodox churches. These churches share a common theology and liturgical practice, emphasizing the importance of the sacraments and the continuity of apostolic tradition. The Eastern Church is distinct from the "Western Church," which is centered around the Roman Catholic Church. The split between the two, known as the Great Schism of 1054, was driven by theological, political, and cultural differences. Today, the Eastern Church continues to play a significant role in global Christianity, maintaining rich traditions and a strong sense of community among its followers.