The great medieval hero of Spanish epic and romance is known even in his own day as El Cid, from an Arabic phrase meaning 'the lord'. His real name is Rodrigo Diaz, and his fame derives from his brilliant successes in the confused warfare of medieval Spain. Christian and Muslim kingdoms at this period compete with each other in ever-shifting alliances - not always along sectarian lines. Rodrigo fights with equal enthusiasm for rulers of either religion.

The main event in his story is the capture of Valencia from the Muslims. He does this on his own account - giving him even more glamour, as a man independent of royal patronage.

Rodrigo is a Castilian, and for most of his fighting life the king of Castile is Alfonso VI. The threat from the new Almoravid dynasty of Muslims causes Alfonso to enlist Rodrigo's help in 1087. Rodrigo drives a hard bargain, securing written agreement that any land he wins from the Muslims will belong to him and to his heirs.

Rodrigo then sets out to conquer Valencia, but soon quarrels with Alfonso. Undeterred he succeeds by 1094 in taking Valencia for himself. He rules it, virtually as king, until his death in 1099.

The historical significance of El Cid's conquest of Valencia is slight, for within three years of his death his widow is driven out by the Muslims. But the sheer effrontery of his personal achievement is enough to inspire the poets.

The first great epic treatment of the theme is the 12th-century Poema de mio Cid. Contemporary with the French chansons de geste, it is like them in presenting its hero as an idealized warrior. From this semi-historical source (written within perhaps half a century of the death of Rodrigo), popular Spanish tradition later evolves ever more fanciful tales about the brave hero.