The document summarizes the Crusades that took place between 1095 and 1291. It discusses the reasons for launching the Crusades, including calls from the Byzantine Empire for aid and the Pope's desire to unite the Christian faith. It then outlines the major Crusades, including the leaders involved, key battles, and the ultimate failure to recapture and hold Jerusalem despite several efforts. In the end, the Crusades failed in their goals and damaged relations between Christians and Muslims.