Sorry. Hitler owns that one, and that's one record I really don't want to see anyone try to tie, let alone break.
Jinghiz Khan owns the record for sheer speed and efficiency. In 1221, he captured the city of Herat and massacred every man, woman, and child in it, an estimated 1.6 million in a week. If he hadn't run out of bodies he would have hit Hitler's Jewish murders in a month.
But it didn't. In the Bosnian wars of 1992-5 Muslim, Croat (Catholic) and Serb (Orthodox) factions fought for control of Bosnia. The United States intervened in the conflict decisively with air power on the side of the Muslims. The result was the Dayton Peace Accords, negotiated in Dayton, Ohio ansd signed in Paris September 14, 1995. These accords were signed by the Republic of Bosnia-Herzegovina, the Republic of Croatia, and the Federal Republic of Yugoslavia. The accords set up a Republic of Bosnia and Herzegovina consisting of two entities: a Croation-Muslim Federation and a Republica Srpska.
This arrangement has failed the test of time. In October 2002 an article in the International Herald Tribune realistically suggested that it is time to admit defeat. There is no Nation-State of Bosnia-Herzegovina, instead there are, in fact, three separate entities, since a Croat-Muslim Federation is as much a delusion as a country of Bosnia-Herzegovina. This in spite of billions of dollars of international aid, Western involvement in governance and Western troops. More than half the pre-war population was displaced during the 1992-1995 war and as of 1998 fewer than 15% had returned, in spite of the fact that return of refugees was a priority of the Dayton Accords.
Not for Muslims.
Sorry Dude but Stalin has the record of about 21 million...
Stalin's got Hitler beat in numbers.
Just to clarify, my comment regarding Gunness Book of World Records was intended to be whimsical not a serious declaration of fact.
Naturally, I have no idea exactly who those bodies were nor can I say with knowledge that the Serbs were the perpetrators - I was just using a stereotype perception to inject some humor - apparently a failed attempt!
Next time I will tag it appropriately. : )