New to me-"Religious" Massacre-20,000 dead

Yes. On the morning of July 22, 1209, FRENCH Catholic Crusaders murdered twenty thousand men, women and children. Through the stupidy of young Cathars who went out that morning to kill a few of the "Host" they spotted on the bridge to the city, the gate was left open and the Crusaders stormed the city of Beziers, a stronghold of the Cathar movement in Languedoc region of southeastern FRANCE. Pope Innocent lll called for this Crusade of French against French, because the Cathars were heretics. The mis-named Pope was quite sure that these heretics deserved to die. The nobility of northen France were happy to go to war, because winning meant gaining power in a region where they had none. I won't go into the whys and wherefores-anyone interested can look up this incident, and the twenty years of war that followed, or they might be interested in the Spanish Inquisition, rooted in this European Crusade and which rose from people being disagreeable in the extreme about matters of faith. I mention it here because a) religion drove the killing, b) the winners stood to gain power and wealth, c ) everyone involved was, by their reckoning, on the right side, and d) there's nothing new under the sun when it comes to atrocities committed in the name of god.
Bezier was decimated almost 800 years ago. Two car bombs were found in London yesterday. I imagine Pope's soldiers would think of me as a heretic. I know Islamic fundamentalists think my beliefs are those of an infidel. It's okay, because I know the truth. God's on my side.