Religious war
A religious war or holy war (Latin: bellum sacrum) is a war primarily caused or justified by differences in religion. In the modern period, debates are common over the extent to which religious, economic, or ethnic aspects of a conflict predominate in a given war. According to the Encyclopedia of Wars, out of all 1,763 known/recorded historical conflicts, 123, or 6.98%, had religion as their primary cause, and of that percentage, 66, or 53.66%, were related to Islam. Matthew White's The Great Big Book of Horrible Things gives religion as the cause of 13 of the world's 100 deadliest atrocities.