"The Poem of El Cid" follows a traditional pattern of traditional poetry common in world literature.  In this tradition, loyalty is an all-important character trait, and by persevering to find his way back into his lord's favor even though that lord has mistreated him, the Cid is demonstrating the depth of his own character.  It seems that nobility in these ancient tales is delineated by personal refinement, compassion, and faithfulness.  In contrast, Diego and Francisco, cowardly and selfish, show no loyalty to the Cid, and only take advantage of his largesse.

Other famous literary works which follow this traditional pattern include "The Illiad and the Odyssey", "Don Quixote de la Mancha", and ancient Egyptian works from the 12th century.