The Great Schism of 1054 was the culmination of years of theological and political tensions between the Eastern Orthodox and Roman Catholic Churches. The major events and leaders that led to the split included the Fourth Crusade, which saw the Western Church sack Constantinople, and the Great Schism of 1054, which officially separated the two churches. Key leaders in the split included Pope Leo IX and Patriarch Michael I. Additionally, theological disagreements over the role of the Pope, the use of icons, and the nature of the Trinity contributed to the divide.