He was never defeated in a battlefield, even if he made huge progress in the reconquest of Spain from the Islamic forces. He conquered many cities in the east of Spain, and finally Valencia. There he ruled the territory around this major city, establishing what could have been called a kingdom but he always called part of Castile, declaring the territory as belonging to his king. There the king allowed him to meet his wife and daughters, and lived happily until his death.
His sword "Tizona" can still be seen in the Army Museum at Madrid. Soon after his death it became one of the most precious parts of the crown possesssions till recently. This is a very specially forged sword he captured to the arabs, and only recent university studies have achieved a forging process that came close to the excellent properties of the steel. His horse was called "Babieca".
His daugthers were married to top noblemen and his blood became a part of the basement of the oldest noble families. It is said that the present heir to the French throne has family ties with el Cid, among many others.
Because of his noble spirit, intelligence, generosity and battlefield excellence, his fame has been passed down all the generations to nowadays spaniards. His figure is outstanding from the rest of contemporaries by its own right, and he is like a lighthouse for generations to come. Special attention has to be paid however to the fact that his figure was later distorted by the powers of that time (the crown and the church) to their own benefit, making him appear more like an over-religious man, example of how to serve a king, and less a fair, noble spirited but down-to-earth man. He was also called "El que en buena hora nació" (i. e. "The one that, luckily, was born")
Bibliography:
"The world of El Cid, Chronicles of the spanish reconquest", Simon Barton and Richard Fletcher, Manchester University Press. (Manchester, 2000). ISBN 0 71905225 4 (amazon.com, search) (Amazon, Pricescan) hardback, 0 71905226 2 paperback. www.manchesteruniversitypress.co.uk
Fear, A. T. (trans.), "Lives of the Visigothic Fathers", Translated texts for historians, vol 26 (Liverpool, 1997).
Melville, C. and A. Ubaydli (ed. and trans.), "Christians and Moors in Spain", vol. III, Arabic sources (711-1501) (Warminster, 1992).
Menéndez PIdal, R. (ed.) "Cantar de Mio Cid", 3 vols (3rd edn, Madrid, 1954-6).
Michael, I. "Thw poem of the Cid" (Manchester 1975).
Wolf, K.B. (trans), "Conquerors and Chroniclers of Early Medieval Spain", Translated texts for historians, vol. 9, (Liverpool, 1990).