The life and legend of Rodrigo Díaz de Vivar, the legendary Spanish knight known as El Cid, are explored. James Morris, a distinguished historian and biographer, draws upon extensive historical research and primary sources to present a comprehensive account of El Cid's military campaigns, political maneuvering, and enduring impact on Spanish history and culture. The book examines his complex character, navigating the blurred lines between historical fact and the myth that has grown around him over centuries.

James Morris's biography of El Cid is recognized for its scholarly depth and engaging narrative style. Critics have praised Morris's ability to synthesize complex historical events and present a nuanced portrait of a figure central to Spanish identity. The book is considered a significant contribution to the understanding of medieval Iberian history and the enduring mythos of El Cid. It offers a balanced perspective, distinguishing between the historical man and the legendary hero.