The East-West Schism refers to the division of Christianity into two main branches: the Eastern Orthodox Church and the Roman Catholic Church. This split occurred in 1054 AD, primarily due to theological, political, and cultural differences between the Western (Latin) and Eastern (Greek) regions of the Christian world. Key issues included disputes over papal authority and the use of leavened versus unleavened bread in the Eucharist. The schism was marked by mutual excommunications between the leaders of the two churches, namely Pope Leo IX in the West and Patriarch Michael I Cerularius in the East. Over time, these differences solidified, leading to distinct religious practices and beliefs that continue to this day.