Cid Campeador, Ruy, or Rodrigo Diaz de Bivar. Hero of Spanish fiction, aided Sancho of Castile against his brother, Alfonso, King of Aragon. On the death of Sancho, acknowledged Alfonso as king of Castile. He lost the favor of Alfonso and retired from his court, but obtained some aid from him in capturing the city of Valencia from the Moors in 1094, which he ruled until his death. Born about 1040, died about 1099.