Non-Fiction:Barton, Simon and Richard Fletcher. The World of El Cid: Chronicles of the Spanish Reconquista. Manchester University Press, 2001.
For the student of Spanish history who wants to read primary sources in English, this is the best work. While not modestly priced, it is not as expensive as learning Latin, Arabic or medieval Spanish. Works best after reading a more general history such as Fletcher's The Quest for El Cid.
Fletcher, Richard. The Quest for El Cid. Oxford University Press: 1991.
Not so much a biography of El Cid as it is a survey or what we know and do not know about the legendary Castilian warrior. Fletcher spends almost the first half of the book on an overview of Spain from Visgothic times until the eleventh century, but it is time well spent. When he arrives at the Cid's story, the reader understands the political and social forces that turned the tide on Islamic Spain in the eleventh century.
Lowney, Chris. A Vanished World: Medieval Spain's Golden Age Christians, Muslims and Jews
As a general rule, I tend to be suspicious of popular histories that announce their thesis in the title (i.e. how so and so changed the world), and this does not prove to be an exception to that rule. Written looking backwards with 9/11 and the Madrid bombings as a starting point, wistfully (or is that wishfully?) recalls a golden age of cooperation and coexistance in medieval Iberia. On the positive side, the chapters are thematically organized around a series of unique individuals or events that are barely covered in the more general chronological histories of the Reconquista.Nicolle, David. El Cid and the Reconquista 1050 - 1492. Osprey: 1988.
Nicolle, David. The Moors: The Islamic West 7th - 15th Centuries AD. Osprey: 2001.
Both of Osprey's two entries on the subject of Medieval Spain were written by David Nicolle and illustrated by the superb Angus McBride. Unfortunately, both books cover such a vast expanse of time that the amount of material, literary and artistic, devoted to the El Cid era is less than I hoped for. Essential for the wargamer, nonetheless.
Reilly, Bernard. The Kingdom of Leon-Castilla Under King Alfonso VI 1065-1109. University of Pennsylvania Press: 1988. Available online at http://libro.uca.edu/alfonso6/alfonso.htm
Essential reading for the important transitional rule of Alfonso VI. After King Ferdinand I engineered the unification of most of the Christian lands of the north, he left them divided among his sons at his death. The middle son, Alfonso, reunified the lands at the cost of his own brother's lives. While deeply appreciative of Andalusian culture, Alfonso VI was also closely associated with deeply pious and Cluniac clergy. The Kingdom of Leon-Castilla Under King Alfonso VI 1065-1109 details how Alfonso built upon his father's political and military institutions and decisively turned the tide of the Spanish Reconquista in favor of the Christians. This is academic reading, but accessible, both in terms of writing and price - it is freely available online as a pdf.
The Poem of the Cid: Dual Language Edition. Penguin Classics: 1985.
Anyone familiar with the Viking sagas will recognize the epic qualities of The Poem of the Cid, or the Lay of the Cid as it is also known. There is history here, to be sure, but also a healthy dose of myth making...not that there is anything wrong with that.
Fiction:Kay, Guy Gavriel. The Lions of al-Rassan. Harper: 1995.
Beautiful, tragic and evocative of a beautiful time and place that might have been. Read all of Kay's books. Now.
Reilly, Bernard. Journey to Compostela: A Novel of Medieval Pilgrimage and Peril. Combined Publishing: 2001.
Set in an unspecified year during the reign of Alfonso VI, a contest of wills develops between the two protagonists, one a peasant and the other a noble. While very brief and quickly read, it is a good description of the class divide in the early feudal era. For wargamers, it has a few action set pieces that could easily be turned into skirmishing scenarios.