The First Crusade

Fifty years ago, if you asked someone the purpose of the Crusades, he would almost certainly have said it was to take back control of the Holy Land.  Nowadays people will tell you that it was to expand Western European imperialism by whitewashing it with religion.

I started taking a look at this, and was surprised at the very pragmatic reason for the summons of the First Crusade, which took place between 1095 an 1099.

The "western" world, that is, the civilizations outside of the Orient, was divided between Latin Christendom, Islam, and the Byzantine Empire.  The Byzantine Empire was the direct heir of Imperial Rome, assuming it's military and legal structure while removing the locus of the empire from Rome to Constantinople, which had been founded by the Roman Emperor Constantine in 330 AD. 

From the time of the 5th Century, a flow of pilgrims from Europe travelled into Jerusalem. In 1001 AD, the Byzantine emperor made an agreement with the Fatimid Caliph, ruler of the Islamic world, for the protection of Christian pilgrims.  An uneasy but peaceful co-existence between the three civilizations continued until the Seljuk Turks defeated the Byzantines in Manzikert in 1071 and went on to conquer Asia Minor, which had been under Byzantine control. 

This victory and the subsequent establishment of several Muslim states within Asia Minor disrupted the pilgrimage (and trade) routes between Europe and Jersualem and also led to and exacerbated several crises within the Byzantine Empire.  When Alexius I (1081-1118) became the Byzantine Emperor, he succeeded in restoring unity within the empire, and he requested aid from his allies in Western Europe to help expel the Seljuk Turks from Asia Minor.  Thus began the First Crusade.