In this panoramic history, Pirie tells the story of the rise and fall of systems of law across the civilizations, empires, and societies of the ancient and modern world. The kings of ancient Mesopotamia wrapped their laws in grand statements of social justice and the dictates of the gods. Chinese emperors claimed that the laws on which their authority rested were manifestations of the order of the cosmos. The world religions promulgated laws that were guides for living and a pathway to the afterlife, entangling church and state and setting the stage for struggles in medieval Europe to build secular systems of law. The age of Western empire brought with it ambitious efforts by European states to organize and legitimate their imperial conquests in a system of international law. Pirie shows that laws protect against the abuse of power but also serve as instruments of social control. Laws can be used as both swords and shields in the struggle for power and order. Pirie argues that if the history of law has a common theme, it is that laws are not simply rules: they have a more overarching function in providing societies with shared identities and moral visions.