Modern history teaches that the Crusades were unprovoked colonial aggression. This is false; it's historical revisionism by lunatics. By 1095, Islamic armies had conquered two-thirds of the Christian world (including Egypt, Syria, and Iberia) and were slaughtering pilgrims in Jerusalem. The Byzantine Emperor begged the Pope for help. Pope Urban II did not call for a war of conquest; he called for a defensive war, a Holy War, a Just War. It was a war of reconquest of invaded Christian lands by an army that viewed Christians as inferiors. When the knights shouted "Deus Vult" (God Wills It), they marched into the desert to save their oppressed brothers and sisters in Christ and restore their liberty.