This article examines the process by which the social base of revolutionary terrorism in the Russian Empire expanded during the late nineteenth and early twentieth centuries. The author argues that one of the principal factors behind the growth of revolutionary terrorism was not only the development of terrorist organizations themselves, but also the gradual expansion of their social base to include young people, segments of the student body, the radical intelligentsia, socially unstable urban strata, women, and other groups experiencing political alienation and social frustration. Particular attention is devoted to several interrelated issues: the current state of scholarship on the subject; the profile of the typical terrorist bomber; the mechanisms by which terrorist attacks were carried out; the role of the social environment and the press in disseminating a culture of terrorism; the ethics of bomb terrorism as a system of moral justifications for violence; the ideological infrastructure of terrorism, represented by the Narodnaya Volya movement and related organizations, as well as their programmatic texts; the image of the female terrorist and its significance for the expansion of the terrorist milieu; and, finally, the social and political groups that opposed the ideology and practice of bomb terrorism. The article concludes that revolutionary terrorism should be understood not merely as a form of political practice or a collection of underground organizations, but also as a distinct social process possessing its own environment of formation, expansion, ideological self-reproduction, and public resonance.