"This groundbreaking study rediscovers the socialists of Tsarist Russia's imperial borderlands, upending conventional interpretations of working-class politics, the Russian Revolution, and Second International socialism. Based on archival research in eight languages, Revolutionary Social Democracy is the first comparative account of the numerous socialist parties that fought for democracy and workers' power across the entire span of the Russian Empire, from the factories of Warsaw, to the oil fields of Baku, to the autonomous parliament of Finland. By demonstrating that the Russian Revolution was far less Russian than commonly assumed, Eric Blanc challenges long-held assumptions of historians, sociologists, and activists about the dynamics of revolutionary change under autocratic and democratic conditions"--