Beginning in 1903, the Russian Social Democratic Labour Party was divided into opposing sections, one led by Vladimir Lenin, the other by Iulii Martov. Until 1917, Lenin and Martov, an anti-war socialist intellectual from a Jewish background, were equally prominent figures in Russian politics. Both wrote prolifically, and although the books, articles, and pamphlets written by Lenin remain readily available today, those by Martov continue to be difficult to locate in their original Russian or, for that matter, in translation. A Russian-language edition of World Bolshevism was published following Martov’s untimely death in 1923, but it was not until 2000, after decades of censorship, that parts of the book were legally published in Russia. This edition, which includes an introduction by Paul Kellogg, makes Martov’s work available in its complete form to English-speaking audiences for the first time in a hundred years and reintroduces this important thinker to a twenty-first century readership.