A series of seven major and numerous minor campaigns into the Levant by West Europeans between 1095 and 1291. Christians had gone on pilgrimages to the Holy Land during much of the medieval period, but with the arrival of the Seljuk Turks their travels were hampered. After wresting Jerusalem from their fellow Muslims, the Seljuks pushed north and defeated the Byzantine forces at the Battle of Manzikert (1071). Within the next few years, Asia Minor, the chief recruiting ground for Byzantine soldiers, was lost, and the emperor was writing to Western princes and to the pope, seeking mercenaries with which to regain the lost territories. Pope Urban II responded to this appeal by proclaiming the First Crusade in a sermon at Clermont (1095). At the conclusion of this address, the crowd shouted, “God wills it!” and this became the battle cry of the movement. The primary reason for the Crusades was religious, for they constituted a holy war, and following Urban's appeal there was an outpouring of religious enthusiasm. In addition, the pope saw in the Crusades an outlet for the energies of the warring nobles of Europe.
The First Crusade, consisting of about 5,000 fighting men, proceeded overland to Constantinople. Alexius Comnenus, the eastern emperor, was frightened by the group, but he provisioned them well, surrounded them with guards, and got them into Asia Minor. Antioch and Jerusalem were among the places that fell to the Crusaders; victory in the Holy City was followed by frightful slaughter of their enemies.
The Crusaders did not free all the Middle East from Muslim control, but by the establishment of several states in the Levant they maintained a balance of power between Byzantines and Muslims. The fortunes of these states varied, and when Jerusalem was endangered,* organized the Second Crusade in 1147, which ended in defeat at Damascus. By 1187 Saladin had united the Muslims and conquered Jerusalem. This provoked the Third Crusade, called the Crusade of Kings because its leaders were , Richard I, and Philip II. Frederick was drowned; Philip and Richard quarreled until Philip returned to France, leaving Richard in command against Saladin. This campaign resulted in a three-year truce and the granting of free access to Jerusalem for Christian pilgrims.
The crusader states were protected by the semi-monastic orders of Templars* and Hospitallers.* Combining monasticism and militarism, they were to protect pilgrims and wage perpetual war against Muslims. They were unable, however, to stop the more numerous onslaughts of their enemies, hence further crusades were necessary. The few knights who answered's call to the Fourth Crusade were unable to pay the passage charges demanded by the Venetians. This led the two groups to strike a bargain and agree to attack Constantinople. After conquering and sacking the city, the Crusaders set up the Latin Empire of Constantinople and forgot about recovering the Holy Land.
During the thirteenth century there were more crusades such as the Children's Crusade* (1212), the Fifth Crusade against Egypt (1219), the Sixth Crusade led by the excommunicated, and the Seventh Crusade of Louis IX. Each of these failed in its efforts to shore up the Latin crusading kingdom, and in 1291 Acre, the last stronghold of the Christians in the Holy Land, fell to the Muslims, thus ending the eras of the crusades. Despite this failure to achieve their main objective, the Crusaders led Europe to have more contacts with the East. This experience stimulated Western trade and thought, thus bringing to an end Western isolation.
S. Runciman, A History of the Crusades (3 vols., 1951-54); J.A. Brundage,, Motives and Achievements (1964); K.M. Setton (ed.), History of the Crusades (5 vols., two published to date).