In 1095 Alexius Comnenus ruler of the Byzantine Empire sent a plea to Pope Urban II requesting his help in securing the borders of his empire and repelling the Muslims who had invaded the Holy Land. .
Pope Urban after hearing reports of the horrendous acts of the Muslims decided to support Comnenus. Pope Urban called a council of religious men from all over Europe and told them of the atrocities of the Muslim people. He rallied the nobles who were more than willing to fight for more land and for God.
Four men Robert, Duke of Normandy and Hugh of Vermadois, Raymond of Toulouse, Godfrey of Bouillon and Bohemund led the first crusade. With supplies from Emperor Alexius who the Crusader Knights had sworn allegiance too, they advanced to meet the enemy.
The Crusade began with success and the knights captured many cities. However, the heat from walking in a full suit of Armour under a hot sun in summer took its toll on the men. There was not much water and many animals died because of the heat. The knights still continued and captured a lot of lost ground.
Eventually in 1099 after facing many hardships, the Crusaders took control of Jerusalem after a siege of five weeks, which was only ended when the crusaders stormed the city with the use of Belfries. The Crusaders looted, plundered, and killed everything and anyone they found for three days. Finally, the city of Jerusalem was once again under Christian control.
In 1212 a Christian boy named Stephen believing he had had a vision from god telling him to recapture the Holy Land gathered thousands of children to him and set off to do just that. Unfortunately the crusade was a disaster some turned back and others were sold as slaves. I believe the children thought that God would protect them and give them the power to succeed where the knights had failed. .