Ever since Hector de Crèvecœur posed the question, ‘What then is this American, this new man?’ in 1782, North Americans have endlessly ruminated on their uniqueness. Yet they have rarely considered what they have in common with the ‘Other America’, the sister-continent to their south. Such has been the ingrained Protestant providentialism of Anglo-American thinking that Spain’s Atlantic empire has too often been consigned to the shadows of the Black Legend, according to which the greed and depravities of the Old World were visited on the New by Iberian conquistadors and viceroys. The same view is alive and flourishing: in his post-9/11 jeremiad Who Are We? (2004), Samuel Huntington deplores the erosion of America’s national identity by immigration, and the undermining of its culture of Protestant individualism by Hispanic bilingualism, multiculturalism and the denationalization of elites. ‘Fortress America’ is today symbolized by the iron curtain erected on the us–Mexican border to exclude illegal immigrants.

Asymmetries of power in the Americas are reflected in asymmetrical historiographies. Spanish American historians, even those based in us universities, tend to concentrate on Spanish American topics, while exceptionalist views of us history have engendered a widespread parochialism that has survived the strictures of the eminent us historian Herbert Bolton, who in 1932 argued for ‘a broader treatment to supplement the nationalist presentations to which we are accustomed’. Few historians have the experience and staying power to overcome such prejudices and preconceptions. John Elliott’s path-breaking Empires of the Atlantic World assembles a formidable and fascinating array of material, testifying to an impressive breadth and depth of knowledge. Author of pioneering books on Olivares, the ‘modernizing’ minister of Philip IV, Elliott has an unparalleled grasp of 17th-century Spain. After a long and distinguished teaching career at Cambridge, London, Princeton and Oxford, in 1997 he began work on the daunting project that has now been brought to a resoundingly successful conclusion: a comprehensive comparative history of the Spanish and British empires in the Americas.

The strength of the book is the masterly way in which Elliott interrelates and compares the numerous different dimensions of British and Spanish policies in all their economic, political, religious and constitutional complexities. Covering the period from the arrival of the first Spanish and English colonists in the 16th century to the end of the independence struggles (1776–1830), Elliott moves in broadly chronological fashion through a series of comparisons: differing patterns of conquest and settlement, distinct approaches to the indigenous peoples and material resources of the New World, contrasting visions of God, crown, state and empire. The result is a gripping and lavishly produced portrait both of the Spanish and British colonial projects, and of the widely varying social, political and economic orders to which they gave rise.

The magnitude of Elliott’s achievement must be seen in the context of a general reluctance among historians—unlike anthropologists—to undertake the exacting discipline of comparative analysis. They have too often been deterred by mundane professional considerations, such as the burden of retooling or the risk of criticism from resentful specialists. As Elliott pungently observes, ‘where the history of the Americas was concerned, professionalization and atomization moved in tandem’. The few who have attempted comparisons on a continental scale have done so in terms of ‘obvious contrasts’—juxtaposing Britain’s ‘empire of commerce’ with Spain’s ‘empire of conquest’, for instance, or focusing on divergent ‘mindsets’, as in Claudio Véliz’s The New World of the Gothic Fox (1994), which borrows Tolstoy’s metaphor, popularized by Isaiah Berlin, to set the Counter-Reformation rigidity of the Spanish hedgehog against the flexibility and pluralism of the British fox.

Elliott has little time for this ingenious but unpersuasive approach. Nor does he subscribe to the ‘immobilities of fragmentation’ thesis put forward by Louis Harz, who argued in the once influential Founding of New Societies (1964) that the salient characteristics of the metropolitan society continue to condition new social formations issuing from them. On the contrary, Elliott observes that ‘changing ideas and priorities at the centre of empire were reflected in changes in imperial policy, so that the third or fourth generation of settlers might well find itself operating within an imperial framework in which the assumptions and responses of the founding fathers had lost much of their former relevance’. Moreover, British and Spanish America ‘did not remain static but changed over time’; not only did the two sets of colonists interact with the conditions and circumstances in which they found themselves, they were also ‘well aware of each other’s presence’. The Atlantic colonies were not ‘two self-contained cultural worlds’, but parallel projects which borrowed from and influenced each other.