The document discusses the Crusades between the 11th and 13th centuries. It provides background on the role of the Church in Europe and the Muslim conquest of Palestine in the 7th century. Tensions increased as Christian pilgrims faced intolerance. In 1095, Pope Urban II called for the First Crusade to retake Jerusalem and help the Byzantine Empire. Thousands of Europeans joined the Crusades for promises of salvation or wealth. The Crusades had short term effects like temporary land gains but weakened the pope's power in the long run. Europeans were exposed to Arab knowledge and culture.