In 1095 at Council of Clermont, Pope Urban II calls for war to rescue Holy Land from Muslim infidels. The First Crusade (1096) is assembled in response to Emperor Alexius I. The Christians capture Antioch (1098) and Jerusalem (1099). They establish the Crusader States, ruled by Europeans. It is the only successful crusade. The Second Crusade begins after the Seljuk Turks recapture Edessa, one of the Crusader States, in 1144. It is led by King Louis VIII of France and Holy Roman Emperor Conrad III. Crusaders perish in Asia Minor (1147).
Saladin controls Egypt (1171), unites Islam in holy war (jihad) against Christians, recaptures Jerusalem (1187). Third Crusade (1189) under kings of France, England, and Germany fails to reduce Saladin's power. Fourth Crusade (1200–1204)—French knights sack Greek Christian Constantinople, establish Latin empire in Byzantium. Greeks reestablish Orthodox faith (1262).
Children's Crusade (1212)—only one of 30,000 French children and about 200 of 20,000 German children survive to return home. Other Crusades—Fifth, against Egypt (1217), Sixth (1228), Seventh (1248), Eighth (1270). Mamelukes conquer Acre; end of the Crusades (1291).