When, in 1088, Cardinal Otho de Lagery was elected Pope, taking the title Urban II, one of his highest priorities was the capture of the Holy City of Jerusalem from the Muslims, who had conquered it in 1076. Having received an urgent request from Byzantine Emperor Alexios I Komnenos for assistance in the struggle against Islam, Pope Urban II convened a council in the city of Clermont in France in 1095. At what became known as the Council of Clermont, Urban II appealed to the leaders of the Catholic Church assembled before him:
“Christains, hasten to help your brothers in the East, for they are being attacked. Arm for the rescue of Jerusalem under your captain Christ. Wear his cross as your badge. If you are killed your sins will be pardoned.”
With that appeal, the First Crusade was launched. All manner of European, many strong adherents to Catholicism, many common criminals seeking a road to salvation, others seeking riches, began the trek to Jerusalem. Forced to make the entire journey across difficult terrain, and enduring horrendous privations, thousands of knights and others pillaged their way across modern day Turkey on their way to Palestine. By 1099, four years after Urban II proclaimed the urgency of conquering Jerusalem, the Crusaders reached their destination, and a bloody battle against Muslims, with the wholesale persecution of Muslim civilians and Jews alike imposed upon the population and forced conversions a matter of policy, the Crusaders took the city.
The First Crusade is labeled as such (“First”) because it presaged a series of bloody endeavors to rid the land of Islam and to convert or kill Jews.