Crusades as a result of the conflict for a long time. Between church and state West Muslims in the east. Neither side is trying to dominate one another. Due to which Islam spread rapidly causing general panic among Christians in Europe. As mentioned in the 11th century, the Christian has sent forces to strike against Islam.
enthusiasm for pilgrimage for Christians to Jerusalem more than ever at the time Jerusalem fell under the rule. Muslim Christian pilgrims to Jerusalem, so there needs to be a land of their own. For the convenience of the pilgrims even more.