Kamenev, Lev B. (Borisovich) (1883–1936), a Russian revolutionary leader. He became associated with the Bolshevik faction of the Social Democratic party in 1903. Although he was one of V. I. Lenin's closest collaborators, he opposed Lenin's plan to seize power in 1917 and favored establishing a coalition government. He was later reconciled with Lenin and in 1922 was appointed vice-premier. After Lenin's death in 1924, Kamenev initially supported Joseph Stalin's claim to be Lenin's successor but later joined the opposition to Stalin. He was expelled from the Communist party in 1927, readmitted, expelled again in 1932, and again readmitted. In 1934 he became a victim of Stalin's purges and was expelled for the last time. He was later tried for treason and executed.