The Crusades

Islam, Byzantium, and the Latin West

For nearly two hundred years, from 1095 to 1291, popes summoned the knights of western Europe to fight for Jerusalem and the lands around it. The Crusades were among the most consequential events of the Middle Ages. They reshaped relations between Christians, Muslims, and Jews, deepened the split between the Latin West and the Greek East, and gave the papacy a new instrument of power: holy war rewarded with spiritual pardon. To understand them, we must begin with the world that produced them.

Within a century of Muhammad's death in 632, Arab armies had conquered Syria, Palestine, Egypt, North Africa, and most of Spain, lands long ruled by the Christian empire and home to ancient Christian communities. Jerusalem surrendered to the caliph Umar in the 630s, and in 846 raiders plundered the great churches of St. Peter and St. Paul outside the walls of Rome. Christians and Jews under Muslim rule became protected but subordinate peoples, paying a special tax and living under restrictions. At times they lived in relative peace; at times they suffered, as in 1009, when the caliph al-Hakim ordered the Church of the Holy Sepulchre in Jerusalem destroyed.

In the eleventh century the Seljuk Turks, converts to Islam from Central Asia, became the dominant power. In 1071 they crushed the Byzantine army at Manzikert and captured the emperor, and within a decade they held most of Asia Minor. Nicaea, where the bishops had confessed Christ's deity in 325 (the Council of Nicaea), became the seat of a Turkish sultan, and Turkish forces took Jerusalem from the Fatimids of Egypt. Pilgrims brought back reports of danger on the roads, though historians debate how much the Turkish advance worsened conditions.

In March 1095 envoys of the Byzantine emperor Alexius I Comnenus appeared at a church council at Piacenza in Italy, asking for western soldiers to help recover his lost lands. Alexius most likely wanted mercenaries. What he received was something no one had seen before.