The Crusades were launched by the Popes (leaders of the catholic church). The European Kings' Armies March to Places that were occupied by Arab Tribes. The Crusades were unsuccessful, they ended...
The first crusades against the muslims were an aid from the pope and christian countries to the faltering Byzantine Empire which was currently being crushed by the muslims, and a fear that they would...
A common reason was to cleanse their soul. Pilgrimages to the Holy Lands "guaranteed" redemption. Many soldiers had no choice. Their lord/king sent them, and they had to go.
Religion, probably was the biggest reason of all, because during the first crusade the Holy War was started. The Holy War was between the Muslims and the Christians. The purpose of the Holy War was...