Julius Martov or L. Martov (Ма́ртов; real name Yuliy Osipovich Tsederbaum (Russian: Ю́лий О́сипович Цедерба́ум; IPA: [ˈjʉlʲɪj ˈosʲɪpəvʲɪtɕ tsɨdʲɪrˈbaʊm, ˈmartəf]) (November 24, 1873 – April 4, 1923) was a Russian politician who became the leader of the Mensheviks in early twentieth century Russia.