Ivan IV, Russian Ivan Vasilyevich known as Ivan the Terrible, (born Aug. 25, 1530, Kolomenskoye, near Moscow—died March 18, 1584, Moscow), Grand prince of Moscow (1533–84) and first tsar of Russia (1547–84). Crowned tsar in 1547 after a long regency (1533–46), he embarked on wide-ranging reforms, including a centralized administration, church councils that systematized the church’s affairs, and the first national assembly (1549). He also instituted reforms to limit the powers of the boyars. After conquering Kazan (1552) and Astrakhan (1556), he engaged in an unsuccessful war to control Livonia, fighting against Sweden and Poland (1558–83). After the defeat and the suspected treason of several Russian boyars, Ivan formed an oprichnina, a territory separate from the rest of the state and under his personal control. With a large bodyguard, he withdrew into his own entourage and left Russia’s management to others. At the same time, he instituted a reign of terror, executing thousands of boyars and ravaging the city of Novgorod. During the 1570s he married five wives in nine years, and, in a fit of rage, he murdered his son Ivan, his only viable heir, in 1581.
