The Twenty One Worst Things People Have Done To Each Other:

Rank	Death Toll	Cause	Centuries
1	55 million	Second World War	20C
2	40 million	Mao Zedong (mostly famine)	20C
3	40 million	Mongol Conquests	13C
4	36 million	An Lushan Revolt	8C
5	25 million	Fall of the Ming Dynasty	17C
6	20 million	Taiping Rebellion	19C
7	20 million	Annihilation of the American Indians	15C-19C
8	20 million	Iosif Stalin	20C
9	19 million	Mideast Slave Trade	7C-19C
10	18 million	Atlantic Slave Trade	15C-19C
11	17 million	Timur Lenk	14C-15C
12	17 million	British India (mostly famine)	19C
13	15 million	First World War	20C
14	9 million	Russian Civil War	20C
15	8 million	Fall of Rome	3C-5C
16	8 million	Congo Free State	19C-20C
17	7 million	Thirty Years War	17C
18	5 million	Russia's Time of Troubles	16C-17C
19	4 million	Napoleonic Wars	19C
20	3 million	Chinese Civil War	20C
21	3 million	French Wars of Religion	16C
TOTAL	389 MILLION