This volume presents the impressive corpus of studies by Robert I. Burns, S.J., on the topic that he has spent a half-century exploring in meticulous detail: the Crusader Kingdom of Valencia. These studies focus on one of Europe’s greatest medieval monarchs, James the Conqueror of Aragon-Catalonia, who made an enduring contribution to Western civilization. James I ‘the Conqueror’ conquered Mediterranean Spain from Islam during fifty crusading years (1225-1276). Not only did he contend with ‘infidel’ powers around him, he frequently vied with warring Christian neighbours. This book presents a rich depiction of King James’s warrior neighbours, Muslim and Christian, from the king who was his greatest ally and greatest rival, Alfonso X the Learned (1212-1284), to the redoubtable and resourceful al-Azraq, a Muslim adventurer, rebel, and leader of one of the most formidable Islamic countercrusades in Spain. These studies illuminate such themes as cultural conflict and interchange, border tensions and frontier relations, medieval warfare and crusading, piracy, brigandage and reprisals, grievance management, medieval queenship and papal relations, the role of Jews in a pluri-ethnic kingdom, Mudejars and Moriscos, and the warrior heroes of Islam. King James presided over a society more complex than any in Christendom, and these studies unlock the details of this stunning achievement.