This is a scholar's book for scholars. Hussein Fancy has used Ernst Kantorowicz's The King's Two Bodies: a Study in Mediaeval Political Theology (1957) to explain why philosophical debates about sovereignty and religion in medieval Aragon still have great significance. In the course of his research in the archives of that kingdom he saw references to mercenary jihadists from North Africa and Granada that earlier scholars had not completely understood. This caused him to look in Arabic language sources for more information.

Fancy did not intend to write a book on mercenaries, but to explain why religion was a poor guide to understanding both medieval and modern politics. He expected to show that religious identities were essentially rational. That fashionable view of the past, however, did not fit what he was learning about the jenets (Muslim horsemen in the service of the king of Aragon), so he modified his goals.

Mercenaries were nothing new by the thirteenth century, where Fancy's narrative begins, not even Arab and Berber mercenaries. Frederick II of Hohenstaufen had dazzled contemporaries with spectacular Muslim bodyguards who served the same functions as the German bodyguards of Roman emperors - their combination of military prowess, unwavering loyalty, and theatrical display emphasized imperial power. Also, calling attention to classical precedents was always a good idea for rulers who wished to make themselves superior to their nobles and clergy rather than be hemmed in by feudal practices based on relatively recent traditions.

Marc Bloch's study of post-Carolingian Europe, Feudal Society (1939), demonstrated that vassalage varied significantly from place to place. Of course, nobles opposed any challenge to their rights, while their rulers wanted more control over them, and when rulers needed more fighting men, either to oppose neighbors or to put down rebellions, they often found it necessary to hire mercenaries. What made Aragon even more unusual amid this feudal diversity was the royal practice of recruiting Muslim warriors.

This runs counter to a history of Spain based on the Reconquista, a tradition of successfully recovering Muslim-occupied lands which bypasses Castile's complicated conflicts with Aragon and Granada to describe a nation that was proudly and rigorously Catholic, united by the memory of Ferdinand and Isabella, and gloriously rich from its colonies around the world.

This is important for understanding Aragon and Valencia in 1284, when the story begins, because at that moment the kingdom was under siege: French armies were gathering to the north, determined to take revenge for the Sicilian Vespers of two years before; the pope wanted to kill the last surviving members of the Hohenstaufen dynasty; rebel lords wanted a return to the days when they ruled the king rather than the other way around; and the Mudéjares (Muslim subjects) in Valencia had recently rebelled, presumably expecting the ruler of Granada to come to their rescue with Berber and Arab warriors from Morocco. Then as later, Mudéjares prayed for a defeat of the unbelievers that would restore Muslim rule over al-Andalus (Spain).

The African jihadists were called Marīnids, while those who had settled in Granada were known at al-Ghuzāh al-Mujāhidūn and were considered to be the worst of the worst. For this very practical reason King Pere wanted the Ghuzāh to fight for him.

Fancy had the linguistic skills (Latin, Spanish, Catalan, Arabic), the time, and the interest to investigate a seemingly obscure subject that informs us both about medieval attitudes toward multi-culturalism and the modern debate over how to integrate Muslim minorities. He reminds us that Muslim rulers had long employed Christian warriors and Christians Muslim jihadists: as long as they were not required to fight against warriors of their own faith, they could justify their service as weakening their confessional enemies. At times there were hundreds of Ghuzāh serving in the armies of the king of Aragon, fighting as light cavalry (a la jineta).

This would not have been confusing to informed individuals living in the thirteenth and fourteenth centuries - they were aware that Muslims had slave soldiers, that everyone hired mercenaries, and that rulers were often more interested in results than intellectual consistency. Modern readers prefer more consistency and less complexity, and few are interested in historiographical controversies about whether religion had any importance at all or was all-important. Nevertheless, political philosophy was central to the disputes between nineteenth century liberal scholars who wanted to separate theology from politics and conservatives who wanted to make it the center of the national story; it also explains why the Spanish Civil War is perceived so differently by political parties today.

Readers from outside Iberia may be interested in these debates only to the extent that Cultural Studies and post-modern thought can clarify them - but Fancy doubts that is possible. Readers looking for a greater understanding of the Reconquista and the Convivencia (Christians, Muslims and Jews living peacefully together in a multi-cultural state) will not lay down the book optimistic about the future of contemporary Europe. Fancy believes that the jenets made the mutual suspicions of Christians and Muslims worse, not better.

Although Fancy is too subtle and cautious to elaborate on this touchy theme, his complex tale of Christian-Muslim relations suggests that Ferdinand and Isabella were wise to mistrust their Muslim subjects and those who became Conversos. Spain was threatened by independence movements based on nostalgia for feudal traditions and regional autonomy, by religious disputes inside Christendom, and by enemies outside the realm. Thus, ridding themselves of Mudéjares likely to join jihadists coming from Africa was a logical policy for the Catholic Monarchs, regardless of what many Spaniards thought then and now.

Fancy discusses this in his final chapter on secularism and theology, but if historiography is a bloodless clash of political views about what Spain should be - united in faith, language and culture or a vibrant mix of religious and cultural traditions - in Spain competing world-views often led to violence. Fancy's analysis of these themes is probably too subtle for most readers, but scholars who specialize in post-modern thought will find this chapter interesting and provocative. Although Fancy believes that he has restored the theoretical importance of religion to medieval politics, most readers will probably continue to see political figures doing what is necessary, then trying to find ways to justify it, or as driven by religious ideology to foolish extremes.

As I said earlier, this is a scholar's book for scholars. It is well-written, but so dense that most undergraduates and lay readers will not last beyond the introductory chapter. Not that they have to, since Fancy outlines what he intends to do in the middle chapters, but they would miss the intellectual challenges in the final chapter, with its historiographical analysis and commentary.

William L. Urban