There was a conflict between Christian Europe and the Ottoman Empire mainly because when the Ottomans took over the Byzantine Empire, they also took over stretch of land known as the Holy Lands, which included the city of Jerusalem, Antioch, and Tripoli. This caused the Europeans to get angry with the Ottomans, and eventually, Pope Urban II ordered the First Crusade and sent the best kings and their lords to fight against the Muslims, and that started the whole blood feud between these two cultural regions, although there was definitely some resentment before the actual crusades began, they were the first physical manifestation of the animosity between the Christians in Europe and the Muslims in the Middle East.