This article argues that the 'permanent revolution' represented the dominant element in Karl Marx and Friedrich Engels' political discourse, and that it tended to overrule considerations encapsulated in 'historical materialism'. In Marx and Engels's understanding, permanent revolution did not represent a historical shortcut under exceptional circumstances, but the course revolutions in the modern era would normally take. Marx and Engels traced back the pattern to the sixteenth century. It is argued here that, in Marx and Engels, the proletarian revolution does not enter the historical agenda when industrial capitalism reaches the stage of integral development, but immediately after the bourgeois revolution, even in semi-developed countries like Germany and > France where the industrial proletariat formed only a small section of the population. Marx and Engels worked out a political rather than an economic sociology of revolution