One of the most prolific mass murderers in history (probably second only to Mao). His "leadership" in WWII was one of the primary causes of that conflict (Hitler/Stalin non-aggression pact). His purges of the army in the thirties coupled with his lack of preparation for the German attack (he refused to believe it would happen) led to the deaths of millions of Russians and the devastation of the nation. He was a paranoid and a fool and one of the very worst "leaders" to ever plague mankind.