Or take the Albigensian Crusade by the Church and France that, under the pretext of removing religious differences, persecuted and killed more than 1 million people in southern France (Occitania). Cities destroyed, entire populations killed or burned at the stake...The hatred for what happened to the Cathars is still strongly felt today in that region. Wars of Christians against Christians that lasted 20 years. Having read many books on the subject, I deeply feel the pain of Occitania.