Stalin violated many human rights.  He needlessly executed top generals out of fear that they would become more powerful and more beloved than him.  He occupied Eastern Europe after WWII and cracked down on anyone professing a religion.  He signed a non-aggression pact with Hitler in 1939 and divided Poland.  Perhaps the greatest human rights violation in the history of Europe was the Holodomor, an artificially created famine in Ukraine and the Northern Caucasus so that Stalin could export food to the rest of the world while his own people starved.  Stalin collectivized farms in Ukraine and when the farmers resisted (it reminded them too much of serfdom), Stalin ordered the leading farmers, intelligentsia, and religious leaders rounded up, tried before sham trials, and shot.  Stalin ordered government officials to confiscate food to send to the Russian state even if it meant taking away Ukrainians' draft animals and seed stock.  Stalin exported much of this food around the world so that he could boast the success of the Communist state.  Over two million people were known to have died in the Holodomor.