The case of the French Revolution supports the proposition that principles of political legitimacy which shape state identities are linked to domestic social structures, and help determine the resources states mobilize in international competition. To the degree that they are shared across states, legitimacy principles also shape international society. The enactment of a deviant principle of legitimacy by a major power will have systemic consequences because it undermines the existing rules of the game; it may have transformative effects if the efficacy of the new principle is demonstrated in competition. Closer attention should be paid to the complex manner in which new principles interact with existing rules of international society.