Moskva & Tsardom of Russia, 1505-1547
Ivan IV, Grand Prince of Moskva from age 3, proclaimed himself Tsar of All Rus at his coronation in 1547. His state thus became the Tsardom of Russia. "Tsar" was Russian for "emperor", and Ivan indeed was an emperor ruling a multi-ethnic empire that, after 1547, he would greatly expand.
Ivan IV (Ivan the Terrifying)
Ivan IV expands Russia but his ruthless paranoia causes tremendous suffering. He is called "Groznyy", (meaning "Terrifying" rather than the traditional "Terrible").