Nikolai Ivanovich Bukharin was a Russian Marxist, Bolshevik revolutionary, and Soviet politician. He was a member of the Politburo (1924–1929) and Central Committee (1917–1937), chairman of the Communist International (Comintern, 1926–1929), and the editor in chief of Pravda (1918–1929), the journal Bolshevik (1924–1929), Izvestia (1934–1936), and the Great Soviet Encyclopedia. He authored Imperialism and World Economy (1918), The ABC of Communism (1919. co-authored with Yevgeni Preobrazhensky), and Historical Materialism (1921) among others. Initially a supporter of Joseph Stalin after Vladimir Lenin's death, he came to oppose a large number of Stalin's policies and was one of Stalin's most prominent victims during the "Moscow Trials" and purges of the Old Bolsheviks in the late 1930s.