International legitimacy -- Europe and the scope of international society -- Westphalia: the origins of international legitimacy? -- Utrecht: consensus, balance of power, and legitimacy -- Revolutionary and legitimate orders: revolution, war, and the Vienna settlement -- Versailles: the making of an illegitimate order? -- Legitimacy and the dual settlement of 1945 -- Legitimacy after the Cold War -- Legitimacy and rightful membership -- Legitimacy and consensus -- Legitimacy and norms -- Legitimacy and equilibrium.