This essay, rigorous and documented, can be read both as the map of the world that is drawn after the great revolutions in Europe and America (1780-1830), and the history of the political and social evolution of four empires with liberal foundations and their way of addressing the rights of non-metropolitan citizens. The parliaments and ministerial offices of London, Paris, Madrid or Washington alternate with an exciting intellectual journey, which also takes the reader to Cape Town, Calcutta, Havana, Algiers or Port-au-Prince. In short, an exceptional book in contemporary historiography, capable of revealing colonialism and the relations between Europeans, European descendants and the native population on four continents; a story that illuminates and explains much of the world we have inherited and in which we now live.