The Crusades were the Repo Man going to get all those valuable "Chritian Relics" that a certain church wanted.
In doing so they went through villages slaughtering Moslems and Christians who might witness the true goal of the crusades. Many individuals had a sincere heart and believed in a higher calling for the task at hand but they were simply fools to a religion that has spent its entire history acquireing wealth.
When looking for a historical truth always "Follow The Money".