The commander of the armies of Castile, Rodrigo went on to lead the Castilian military campaigns against the King's brothers, as well as against the Muslim kingdoms in Al-Andalus. He became renowned for his military prowess in these campaigns, which helped expand Castilian territory at the expense of the Muslims and Sancho II's brothers' kingdoms. When the King was succeded by one his brothers, El Cid was ordered into exile by the rancorous new King.
El Cid found work fighting for the Muslim rulers of Zaragoza, whom he defended from their traditional enemies, Aragon and Barcelona. He repeatedly turned out victorious in battle against the Muslim rulers of Lérida and their Christian allies. In 1086, an expeditionary army of North African Almoravids inflicted a severe defeat to Castile, compelling King Alfonso to overcome the resentments he harbored against El Cid and Rodrigo soon found himself fighting for his former Lord.
Over the next several years, however, El Cid set his sights on the kingdom-city of Valencia, operating more or less independently of Alfonso and gradually increased his control over Valencia; establishing an independent principality. He ruled over a pluralistic society with the popular support of Christians and Muslims alike.
After his death, he became Castile's celebrated national hero and a legendary figure of the Spanish folklore. In 1492, the Assassins recovered documents claiming that El Cid was once in possession of a powerful artifact which his wife absconded with and hide after his death. Decided to investigate the matter, the Spanish Assassins tried to recover the artifact before the Templars but Inquisitor Gustavo Ramirez found it first.
- The sub-story of El Cid and his connection to the Staff of Eden was originally unveiled by completing Legacy Missions in the early builds of AC: Rebellion, but it was eventually removed.