DEUTSCH, LEO (Lev Grigoryevich ; 1855–1941), Russian revolutionary. Deutsch was born in Tulchin (Kamenets Podolsk) and in the 1870s joined the Populist Narodniki. In 1877 he organized a revolt of farmers in the district of Chigirin (Ukraine); he was arrested but escaped to Switzerland. In 1879 he returned to Peterburg and was a member of the revolutionary organization Ẓemlia i Volia" ("Earth and Freedom"), and later of "Chornyi Peredel." In 1880 he immigrated to Switzerland, and with Plekhanov, Akselrod, and others in 1883 they founded "Osvobozhdenie Truda" ("Liberation of Labor"), the first Russian Marxist group abroad. In 1884 he was arrested in Germany and was handed over to the Russian government. After 16 years of hard labor he escaped to Switzerland again (1901). His experiences were published in Sixteen Years in Siberia (London, 1903; Russian ed. 1924), which was translated into many languages. He sided with the Mensheviks in 1903. In 1905 he returned to Russia, was arrested and escaped again, and lived in London from 1907 to 1911 and in the U.S. from 1911to 1916. After the February Revolution he returned to Russia. Since his attitude toward the October Revolution was negative, he gave up politics. He concerned himself with editing Plekhanov's works. In his later years he was mainly occupied with the history of the Russian revolutionary movement. Only the first volume of his work Rol yevreyev v russkom revolyutsionnom dvizhenii ("The Role of the Jews in the Russian Revolutionary Movement," 1923) was ever published.