Most brutal and degenerate war in human history

[Anarchy666]

I'm not talking about WW2, the largest war, I'm talking about the sheer level of brutality and barbarity involved. What would you say is the most degenerate and regressive war in human history? No wrong answer (unless you're a ******* retard of course)

 

[lg325]

American Civil War, Some the wars in ancient times were a nightmare for those who served in them.

 

[Auld Phart]

I believe Genghis holds the record

 

[Hyddan92]

Iran-Iraq war is a good contender.