 The attacks may have originated in the belief that Jews and Muslims were equally enemies of Christ, and enemies were to be fought or converted to Christianity.Godfrey of Bouillon was rumoured to have extorted money from the Jews of Cologne and Mainz, and many of the Crusaders wondered why they should travel thousands of miles to fight non-believers when there were already non-believers closer to home.The four main crusader armies left Europe around the appointed time in August 1096.