The Crusades were a series of military excursions led by European armies, starting in the early eleventh century. They were a battle between religions, Muslim versus Christian, for over five hundred years. Contrary to popular belief, the Crusades were not simply a means for Christian countries to gain wealth, land, and economic resources (although, they did obtain these in the process).

For the Christians, Crusading was the only way to ward off a potential attack from Islamic forces. The Christian Crusade was an "Attack them first before they attack us." In - - - - - - - - Muslim conquest before 1 st crusade - - - - - - - - - - - - -. In 1071, the Muslim Seljuk Turks destroyed the Byzantine army at the battle of Manzikert. This led the Byzantine Emperor to summon the European Christians for aid. The Byzantine Emperor sent a letter to Pope Urban II calling for help.

The Pope then held a council at Clermont, France. At this council, he brought together a large audience of European nobles, clergy, and knights. For ten days, he urged them to take up arms against the infidels.

"Let those who have been robbers, now become Knights. Let those who have been fighting their brothers now fight against the barbarians. Let those who have been serving as mercenaries for small pay, now obtain an eternal reward!"

With these last words, the excited assembly erupted as one voice shouting, Deus Vult! (God wills it!).

The Pope promised that anyone who went to go fight against the Muslims, and recapture Jerusalem (or died in route), would receive eternal life in Heaven. This later led to the “Indulgences” made famous in the 16th century. The Protestant Reformer Martin Luther mainly led the Reformation against the act of selling indulgences. He proclaimed, contradicting the Catholic Church, that only by Gods Grace (Sola Gratia) are you saved from eternal judgment.