Histories of the origins of the idea of ‘Europe’ have probed the legacies of the Roman Empire, the concept of western Christendom, and the power of the ‘republic of letters’ in the dissemination of ‘Enlightenment’ ideas, culminating in the cosmopolitanism of the early years of the French Revolution. Anthony Pagden is well aware of this heritage but has decided to begin his own study with Napoleon. It seems a strange choice, since the emperor’s European dream was always of a French imperium, whatever the toll in lives; but it does serve to highlight the later triumph of the European Union in securing continental peace. The Napoleonic wars of 1799–1815 cost at least four million lives, World War I twenty million, and World War II eighteen million in Europe alone. After 1799, France was invaded by Prussian or German armies five times: in 1813, 1815, 1870–71, 1914–18, and 1940–44. Somehow, a Franco-German entente after 1945 and incremental expansion of EU membership have since created a supranational structure, now of twenty-seven members, and a continent largely free of international warfare for nearly eighty years.