Ivan IV(redirected from Ivan IV of Russia)
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Related to Ivan IV of Russia: Ivan VI of Russia
(Biography) known as Ivan the Terrible. 1530–84, grand duke of Muscovy (1533–47) and first tsar of Russia (1547–84). He conquered Kazan (1552), Astrakhan (1556), and Siberia (1581), but was defeated by Poland in the Livonian War (1558–82) after which his rule became increasingly oppressive