Rodrigo Díaz de Vivar was a Castilian knight and warlord in medieval Spain (d. 1099).
Fighting with both Christian and Muslim armies during his lifetime, he earned the honorary
titles El Cid (the lord, the master), and El Campeador (the valiant). El Cid became Spain's
celebrated national hero and a representative of the ideal medieval knight: strong, valiant,
loyal, just, and pious. (Wikipedia)