Why Did the Crusades Happen?

The Crusades were sanctioned and fought due to the faulty idea that Christianity could be forced upon a people and land. They were fought mainly against Muslims, but also involved campaigns against the French, pagan Slavs, Jews, Russian and Greek Orthodox Christians, Mongols, Cathars, Hussites, Waldensians, Old Prussians and the pope’s political enemies. The Crusades lasted for a period of about 200 years and sought to restore Christian control over the Holy Land and Jerusalem. You can find more information here: