Presenting the first specific “case” of vanguardism, this chapter analyzes vanguard ideology and organizations that founded themselves on economic, class-based mass populations, with the primary focus on vanguard parties based on proletarian populations. After differentiating between vanguardist “class” and anarchist focus on “the people”, the chapter discusses the specific quality of the class-based organization. Beginning from a materialist foundation that perceives the economic class as gaining epistemological insight through its simultaneous social positions as central productive force and most oppressed/alienated population, class-based vanguards argue that the overwhelming ideational power of the Enemy category (the bourgeoisie) prevents the class from seeking revolution. As the class needs direction, but also remains the true power for revolution, class-based vanguard parties tend to follow “democratic centralism” as a means of maintaining control while also legitimating their rule as mere guidance. Particular attention is paid to the Bolshevik organization and Marxism-Leninism, with additional emphasis on contributions by Trotsky, Stalin, Mao, and Bukharin, as well as divisions between this form of vanguardism and Western Marxism.