I've long thought that atheists--in the guise of Communism, Socialism, the so-called "progressives" and environmentalists--have killed more people than all religions combined. I still think I may be correct, but this article discussing the murderous history of Islam gives me some pause. Mike Konrad notes:
-- "[T]he Indian (subcontinent) population decreased by 80 million between 1000 (conquest of Afghanistan) and 1525 (end of Delhi Sultanate)[.]"
--"[T]he death toll from 1400 years of Arab and Muslim slave raids into Africa could have been as high as 112 Millions. When added to the number of those sold in the slave markets, the total number of African victims of the trans-Saharan and East African slave trade could be significantly higher than 140 Million people." He goes on to observe that adding in the killing in the Sudan during the 20th Century probably brings the total above 200,000,000.
--Also, "for the 250 years between 1530 and 1780, the figure [number of Europeans killed by the Muslim Barbary pirates] could easily have been as high as 1,250,000." Additional millions may have been killed by attempted invasions of Italy and Southern Europe.
--"Don't forget the 1.5 million Armenian Christians killed by the Turks during WWI."
He observes that we do not know the numbers killed in South East Asia and the Orient by Muslim aggression, nor the indirect impact caused by Muslim destroying almost every civilization in which it came into contact. Large Jewish and Christian populations once existed in the Middle-East, but are now all but extinct. Where did they go? They can't have all been converted.