Where does international order come from? How is it established and maintained? Why does it break down? With every sovereign state its own master, how can order prevail? Answering these questions in a briskly paced, systematic survey, the author explores the rise and fall of successive international systems across the centuries-from the dynastic institutions of Renaissance Europe, to the power-politics systems of eighteenth- and nineteenth-century Europe, to the liberal international systems of the contemporary world.