The Romans, with the destruction of Jerusalem in 70 AD, named the lands of the birthplace of Christ Palestine.8 The Holy Land has always been the spiritual home and symbol of the Christian faith. Following Constantine's Edict of Milan in 313 ending Christian persecution, pilgrimages to Jerusalem became safe for those who had the means of travel.
The founding of Islam by Mohammed (570-632) changed the complexion of the Middle East. The concept of holy war, or jihad, to expand religious aims was embraced by the followers of Islam. The Muslims captured Jerusalem in 638, and the Patriarchates of Jerusalem, Antioch, and Alexandria were placed under the control of the Caliphates. However, Islam proved a tolerant religion in victory, in keeping with the teachings of Mohammed. The Church of the Holy Sepulchre in Jerusalem was allowed to remain Christian, and Christians were allowed to practice their religion with the payment of a special tax, called the jizya. The Moslem invasion captured the eastern part of the Byzantine empire but twice they were held off at Constantinople, decisively in 717 by Emperor Leo III.
By the next century, Islam under the Umayyad Dynasty extended all the way from India through Morocco into Spain. It was only their defeat by Charles Martel at the Battle of Tours in 732 that stopped the Western European advance of Mohammedan forces.3, 9 But the Reconquista of Spain, or the unification of Spain under Christian rule, was not completed until the reign of Ferdinand and Isabella, when Granada was captured from the Moors on January 2, 1492.
Events turned for the worse in the East, however, in the beginning of the eleventh century.
The Church of the Holy Sepulchre, which was completed in 335 on the site of Christ's crucifixion, burial, and resurrection, was destroyed in 1009 by a Fatimid Caliph.10 A new wave of Moslem aggression by the Seljuk Turks led to Christian persecution in the Holy Land and the invasion of the Byzantine Empire. The defeat of the Byzantines at the decisive Battle of Manzikert in 1071 gave the Seljuk Turks possession of Asia Minor. Nicaea and then Antioch fell to the Turks. Constantinople was vulnerable, and pilgrimages to the Holy Land abruptly ended. This led Byzantine Emperor Alexius I Comnenus to appeal to Pope Urban II for help. The Emperor sent his emissaries to the Pope's Council of Piacenza in the March of 1095, with a request for knights to defend the East.