The famous Spanish poem Cantar del mio Cid tells the story of the legendary El Cid, a Spanish hero in the war between the Christians and Moors. The poem was based on a real man, Rodrigo Diaz de Vivar (c. 1043-1099). He actually was a mercenary who fought on both sides. His name "El Cid" comes from the Arabic al sayyid meaning "the lord.'