First Crusade
Launched at the call of Pope Urban II, the crusade captured Jerusalem in 1099 and founded the Kingdom of Jerusalem.
In the 11th century the Seljuk Turks entered Baghdad, received the title of sultan from the Abbasid caliph, and after crushing a Byzantine army at Manzikert in 1071 pushed into Anatolia. When the threatened Byzantine emperor Alexios I asked the West for help, Pope Urban II called for the recovery of the Holy Land at the Council of Clermont in 1095. The pope hoped to reunite the Eastern and Western churches and raise papal authority; knights seeking land, merchants eyeing eastern trade and peasants hoping for forgiveness of sins and a new life all answered for their own reasons.
Some of the popular bands that set out first massacred Jews in the Rhineland, and the followers of Peter the Hermit were wiped out by the Seljuks in Anatolia in 1096. Then armies of knights led by French and Norman princes gathered at Constantinople and, by way of Nicaea (1097) and Antioch (1098), took Jerusalem in 1099. Division in the Islamic world between Seljuk powers and the Fatimids worked in the crusaders’ favour.
Crusader states, led by the Kingdom of Jerusalem, were founded on the conquered land. But the crusaders did not hand their conquests back to Byzantium, breeding mistrust between the two Christian worlds, and the Islamic world gradually rallied under the banner of jihad. The First Crusade was the only one to take Jerusalem by force, and it began some two hundred years of crusading.