Albigensian Crusade

During Medieval France, a new religious movement known as the Cathars was rapidly growing in popularity. In simplified terms, the new religion believed that the Catholic God was a satanic being, they worship his more benevolent counterpart. Both deities created this world, but the evil god has trapped Humanity in a belief similar to the Buddhist cycle of rebirth. Their sexual teachings were the mirror opposite of the Catholic Church. The Catholic Church taught that sexual behaviors that were reproductive in nature was better then non-preventive sex. The Cathars taught the exact opposite of that teaching. This has led to Catholic propaganda that Cathars were homosexual. The Cathars were also had women in almost identical roles to men, which was horrifying to the Catholics at that time. Several key differences among the two faiths along with political reasons led to tensions so high that the Catholic Church ordered a genocidal crusade against the Cathars. The Cathars were theoretically pacifists, but they were not above hiring mercenaries for the obvious practical reasons. The Crusade was fought with a series of massacres of Cathars and sieges on Cathar castles. On notable siege on the Cathar Castle of Toulouse, Simon de Montifort, one of the Crusader generals was killed when a projectile from a Cathar catapult hit Simon in the head. However, the Crusades ended with a Crusader victory with the Cathars theoretically wiped out.