From the twentieth-century revival of interest in the “School of Salamanca” to more recent discussions of the so-called “doctrine of discovery,” many observers have recognized that, before the Enlightenment, European arguments both for and against imperial conquest and slavery were deeply rooted in Christian theology and canon law. Scholars such as Brian Tierney, James Muldoon, and Anthony Pagden have examined such arguments learnedly, but their treatment of Spanish imperialist discourse has centered mainly on the Americas. The Other Side of Empire aims to broaden the geographic scope of this inquiry by showing that Spanish arguments legitimating conquest in the new world had roots in an earlier chapter of Spanish expansion in the Mediterranean. Devereux's six lucid chapters examine Spanish arguments for empire in North Africa, Italy, and the eastern Mediterranean from c. 1450 to c. 1516, arguing that 1492 was “part of a continuum along which Christian jurists attempted to work out thorny questions surrounding just war, conquest, and who could possess dominium” (12). Not only did Spanish imperial ventures in the Mediterranean provide ample precedents for the apologists of Spain's American conquests, but many of these apologists, and their critics, were the same people.

Devereux's “Mediterranean moment” (98) aligns mainly with the reign of Ferdinand of Aragon (r. 1479–1516), and the book thus centers largely on his foreign policy. But Devereux's first two chapters make Ferdinand's geographical, political, and intellectual contexts admirably accessible to non-specialists. As the center of the known ancient world, the Mediterranean was inevitably the starting point for Spanish thinking about empire and religion. It was also the center of Ferdinand's political ambitions. His self-image as the defensor pacis, a Christian ruler called to protect not only his own subjects but Christendom at large, reflected both the weakening of the papacy and the rise of the Ottoman Empire. After conquering Constantinople in 1453, the Ottomans continued to expand westward and posed an existential threat to European Christians. The Ottoman conquest of Jerusalem in 1516 dramatized the failure of Ferdinand's Mediterranean policy but did not end Spanish preoccupations with defending Christendom against what seemed an “unstoppable Islamic foe” (58).

In this context, Catholic jurists agreed that even wars between Christian monarchs could be described as “just wars” if they aimed to protect Christendom's sensitive frontiers against enemies of the faith. Sometimes these were also seen as holy wars. Chapter 3 revisits the Habsburg-Valois rivalry over Italy in this light, showing how Juan López de Palacios Rubios interpreted the Spanish campaign against France and Alonso de Cartagena as a “holy war” because it was waged against a “schismatic” French king who challenged papal supremacy (90). Chapters 4 and 5 show how Ferdinand deployed the idea of Christian crusade and the title of “King of Jerusalem” (which he claimed after wresting Naples from France in 1504) to justify a string of conquests in North Africa and planned conquests in Asia. Some such claims were couched as “the recovery of lost patrimony” (99) on the basis of exaggerated historical claims. But others invoked papal authority, embracing the argument first made by Hostiensis (d. 1271) that Christ had bequeathed all worldly authority (dominium) to the pope, who could grant it to particular Christian monarchs at will.

At first glance, Devereux's crusade-obsessed Ferdinand seems the antithesis of the cynical king whom Machiavelli characterized as “always preaching peace and good faith [though] he has not a shred of respect for either” (Prince, chapter 18). But Devereux cares less to establish Ferdinand's sincerity than to show that his political rhetoric formed a coherent whole. “Even if this language had the potential to be used cynically,” he argues, “it also had the potential to be understood sincerely.” (94) The core of this discourse was defense of the fragile respublica christiana from Muslim antagonists. Devereux lets the reader decide whether Spanish “holy war” and “just war” propaganda was cynical or sincere in particular instances, but he suggests that Ferdinand genuinely believed such conquests would please God and liberate Christian subjects from Muslim rule.

The Spanish conquest of America, of course, differed in fundamental ways from these Mediterranean ventures. The Americas were not part of the known world, and their people were unfamiliar Gentiles never before ruled by Christians. All these facts rendered many of the arguments from the Mediterranean theater inapplicable to the Americas. Devereux acknowledges that “the American arguments” therefore took “quite [a] different course” (180) but refrains from trying to revise the established narrative of Spanish American imperialism. Some readers may find this restraint disappointing, but Devereux certainly opens the way for others to pursue the question of how the “Mediterranean moment” might lead us to reconsider the better-known Atlantic one.

Chapter 4, “The African Horizon,” does suggest a few important answers. Here Devereux carefully compares the Spanish jurists’ application of papal bulls to Spanish claims in Africa and the Americas, showing that while both invoked papal bulls, claims to Africa were also defended as acts of recuperation. Only in the Americas was conquest justified purely on grounds of evangelization. For Africa, the jurists placed more weight on the argument that Christians had ruled there before. The same distinction underlay arguments for enslaving Africans but not Americans. Enslaved Africans were often identified as Moors, thus associating them with Muslim parts of Africa and making their enslavement a matter of licit punishment for the oppressors of Christianity. By this reasoning, the indigenous Americans did not deserve to be enslaved unless they forcibly resisted the preaching of the Gospel. Bartolomé de las Casas made this argument more fervently than anyone, but he was not the only Spanish theologian to insist that neither territorial displacement nor physical enslavement could be justified simply on the grounds that people were not Christian or were allegedly less civilized. While Devereux does not draw out this conclusion in detail, he seems to be suggesting, quite plausibly, that the earliest European justifications for slavery had more to do with cultural and religious assumptions than with racial ones, and that what look in hindsight like eternal European attitudes of cultural superiority actually began as defensive postures by people who felt threatened and insecure.

This learned treatment of Spain's Mediterranean empire under Ferdinand is essential reading for scholars of early modern Europe, and should generate fruitful discussion among those interested in broader questions of Christian empires and their legal, moral, and intellectual foundations.