FTP, identify this man essentially succeeded by Boris Godunov, the first Russian tsar.
He opened trade with England through the Muscovy Company and conquered Kazan and Astrakhan.  His reign saw the unsuccessful Livonian War, as well as the execution of Filipp Kolych?, head of the church, and Prince Vladimir Staritsky, his chosen successor, during a period of oppression known as the oprichnina.  He farcically abdicated for a year in favor of Simeon Bekbulatovich in 1575, and later killed his heir Ivan Ivanovich, leaving his feebleminded son Fyodor as the only heir.  FTP, identify this man essentially succeeded by Boris Godunov, the first Russian tsar.
He opened trade with England through the Muscovy Company and conquered Kazan and Astrakhan.  
Ivan IV or Ivan the Terrible or Ivan Groznyi