The Victors and the Vanquished: Christians and Muslims in Catalonia and Aragon, 1050–1300
   	      (Cambridge: Cambridge University Press, 2004) 
This revisionary study of Muslims living under Christian rule during the Spanish "reconquest" delves into the subtleties of identity under the thirteenth-century Crown rule of Aragon. Brian Catlos uncovers a social dynamic in which sectarian differences comprise only one of the many factors in the causal complex of political, economic and cultural reactions. Beginning with the final stage of independent Muslim rule in the Ebro valley region, he traces the subtle and often surprising transformation of Islamic society into mudéjar society under Christian domination.
- winner Premio del Rey (The American Historical Association), 2006;
 
- winner John E. Fagg Prize (The American Historical Association), 2005.

  Spanish translation: Vencedores y vencidos: Cristianos y musulmanes de Cataluña y Aragón, 1050–1300
(Valencia: Universitat de València, 2009) 
Reviews
- Journal of Semetic Studies 55 (2010);
- Studies in Medieval and Renaissance Teaching 16 (2009);
- Studi Medievali 50 (2009);
- History 92 (2007);
- Le Moyen Age 93 (2007);
- Medieval Encounters 13 (2007);
- Cahiers du Civilisation Médièvale 59 (2007);
- American Historical Review 110 (2006);
- English Historical Review 121 (2006);
- AARHMS Newsletter (Fall 2006);
- SSHPS Bulletin (Fall 2006);
- The Medieval Review (05/13/05);
- Anuario de Estudios Medievales 35 (2005);
- Annales: Histoire, Sciences Sociales 59 (2004).
See also Vencedores y vencidos
"an excellent piece of historiography" 
- Sam Conedera, History, UCLA
"The  author aims for, and delivers, far more than a simple narrative or  description of the mudejar, or subject Muslim, population....  discussions of theory of intercultural relations, which are woven  throughout the book, add depth and sophistication to the analysis of the  extensive archival documentation undergirding this impressive study." 
-Medieval Encounters, Anne Marie Wolf, University of Portland
"...such  creative interdisciplinary forays are precisely what recommend this  well-conceived, meticulously researched, and ultimately convincing book  to an audience beyond scholars of medieval Spanish history." 
- American Historical Review, Adam J. Kosto, Columbia University
"This  is an ambitious, mature and comprehensive work on a topic that [Catlos]  knows well. Undergraduate and postgraduate students along with  specialists can learn a great deal from a book that put forward a  challenging interpretation in a clear and concise style. The book is  clever in structure." 
- The Medieval Review, Esther Pascua, University of St. Andrews
"There  is no doubt that this complex and intricate study of Muslim Christian  relations, based on archival sources and a vast bibliography, is not  only unusually well written, but it adds significantly to our  understanding of the years 1050 to 1300 in Catalonia and Aragon.  Furthermore, it is probably the most comprehensive account available of  the social dynamics which made up medieval Spain before 1300... Catlos  has chosen a difficult subject and has produced an outstanding  contribution to the field, a volume which will long remain the standard  reference for students of Muslim/Christian relations prior to 1300." 
- AARHMS Newsletter, Jill Webster, St. Michael's College, University of Toronto
"a  ground-breaking study that brings to life a hitherto neglected culture  and population, more than deserving of our attention. It is also a model  of how such archivally based studies can illuminate a society for which  few narrative sources are available... [there is] wealth of insights  and argument contained in what is a remarkable, and also highly  readable, work of scholarship." 
- EHR, Roger Collins, University of Edinburgh
"Taken  as a whole, this is an extremely important contribution to existing  scholarship and to the ongoing debate over the nature of  Christian-Muslim social interaction during the middle ages." 
- History, Simon Barton, University of Exeter 
