What you describe happened mostly to Africans
If Africans waged war against other nations, the other nations that won would enslave the people and sell them on the market. If they waged war between themselves, the stronger tribes would enslave the weaker tribes and sell them to the slave market even though they are more or less neighbors.
The Five areas that have religious conflicts were (1) Abyssinia - Somalia war from 1529 until 1559. (2) Nigerian conflict, it is between Riots against Igbo an inter-ethnic conflict in Nigeria from 1953 until the 1960's. (3) The Buddhist uprising, in Vietnam the Buddhist were in majority up to 70 to 90 percent. Ngo Dinh Diem in south Vietnam the discrimination against the Buddhist were generated that lead them to uprising. (4) Chinese Conflict, the Dungan revolt between Uyghurs and the Hui, a rebellion broke out with Hui leader General Ma bufang massacred fellow muslims, the Kazakhs (5) Lebanese Civil War, conflict between three religion lines, the Sunni Muslims, Christian Lebanese and Shiite Muslims.
War and disease are two major ones
