The novel that I read for my independent novel study is called "Sashenka". It's by Simon Montefiore and explores the event of the Russian Revolution, as well as it's aftermath, in great detail (and I do mean great. If you get bored easily, this book is not for you).
The Russian Revolution occured in 1917, and was basically a revolt against the Tsarist dictatorship in Russia. The revolters, or "Bolsheviks", were lead by Josef Stalin. Once the Bolsheviks gained power, they destroyed everybody that opposed them. Some of these people were shot. Others were imprisoned. Many were beaten to death.
Eventually, there were no more enemies to kill. The Bolsheviks were somewhat relieved, because many of the people that were killed had been friends of theirs. They hoped that this was the end of the bloodshed, but they were wrong. Soon, the Bolsheviks were being killed. Everybody was up for investigation. Not even those that had been Bolsheviks from the very start were safe. This political liquidation killed hundreds, possibly thousands. Some say that it was a more brutal time in history than World War Two.