The world’s costliest civil war, in terms of the number of lives lost during combat and in events directly relating to the war, is the Russian Civil War of 1917-22. It is estimated that the former Soviet Union lost 939,755 soldiers, and over 8 million civilians died following armed attacks, famine and disease.

The Russian Civil War was a direct result of the 1917 October Revolution which resulted in the down-fall of the Tsar. The main sides in the conflict were the anti-Bolsheviks (Whites) and the Bolsheviks (Red Army).