Simple
Year the great schism between the Roman Catholic Church and the Eastern Orthodox church, occurred.
What is 1054?
The difference in political beliefs that distinctly separated the two churches.
What is the belief in papacy and caesaropapism?
The half where the Byzantine empire had most of the control.
What is the Eastern?
The way in which the Sunni and Shia split in Islam is similar to the schism between the Roman Catholic church and the Eastern Orthodox Church.
What is the fact that they both split because of them not being able to agree on who should be in charge when talking about the political aspect of life in the Christendom?
The name of the two churches in Europe that excommunicated each other.
What is the Roman Catholic Church and the Eastern Orthodox Church?
The belief that separated the Sunni and Shia sects.
What is who should become successor (Ali or Abu Bakr)?