Description:The Socialist Revolutionary Party (PSR) played an important role in the history of the Russian revolutionary movement. The author seeks to explain why this party--which continued the tradition of the 1870s--did not ultimately prevail in an agrarian country like the Tsarist empire. Using a wealth of printed sources and, for the first time, drawing upon materials from the archive of the Central Committee of the PSR, this study provides a detailed analysis of the theoretical foundations the party as well as its organizational structure and political practice during the first Russian Revolution.