When a historian writes “The Church”, he or she only means one thing – the Catholic Church. For many hundreds of years, the Catholic Church was really the only Christian church in Europe. Or at least in western, central and northern Europe. In Russia and the Byzantine Empire, which included much of the Balkan peninsula, the Orthodox faith held sway. Both the pope in Rome and the Patriarch of the Orthodox Church in Constantinople worked tirelessly to make theirs the ONLY Christian church, but despite much bloodshed and treasure spent, neither one could gain the upper hand in the others' territories.