He was born Rodrigo (or Ruy) Díaz de Vivar. Vivar being the town where he was born. It is near Burgos. He was born either in 1040 or 1043. Historians are not sure of the date. He died in Valencia in 1099. His name, “El Cid” was given to him by the Moors. In the mixture of the Spanish and Arabic language they used, they called him “As-Sid” (Lord or Chief). This was pronounced by the Spaniards as “El Cid”, but they themselves actually called him “Campeador” (Champion).
Muslim General Ben Yusuf (Herbert Lom) of the Almoravid dynasty has summoned all the Emirs of Al-Andalus to North Africa and chastises them for their complacency in dealing with the infidels and reveals his plan for Islamic world domination. Later, while en route to his future bride Doña Jimena (Sophia Loren), Don Rodrigo, (Charlton Heston) becomes involved in a battle against a Moorish army. Two of the Emirs, Al-Mu’tamin (Douglas Wilmer) of Zaragosa and Al-Kabir (Frank Thring) of Valencia are captured, but Rodrigo releases them on condition that they never again attack King Ferdinand of Castile (Ralph Truman). The Emirs proclaim him ‘El Cid’ (the Castillian Spanish pronunciation of the Arabic for Lord: “Al Sidi”) and swear allegiance to him. For this act he is accused of treason against the King by Jimena’s father, Count Gormaz (Andrew Cruickshank). Rodrigo’s proud father, Don Diego (Michael Hordern) challenges Gormaz, and when Gormaz refuses to take back the challenge or the accusation of treason, Rodrigo kills him in a duel. Jimena swears revenge upon her father’s murderer. Rodrigo then takes up the mantle of the King’s champion in single combat for control of the city of Calahorra, which he wins. Rodrigo is then sent upon a mission to collect tribute from Moorish vassals of the Castillian crown, but Jimena, in league with Count Ordóñez (Raf Vallone), has plotted to have Rodrigo killed. El Cid and his men are ambushed but are saved by Al-Mu’tamin, to whom he had previously showed clemency. Returning home, his reward is the hand of Jimena in marriage. But the marriage is not consummated and she removes herself to a convent.
King Ferdinand dies, and his eldest son, Prince Sancho (Gary Raymond), becomes king. The younger son, Prince Alfonso (John Fraser) also desires the throne; with his sister, Princess Urraca (Geneviève Page), Alfonso has Sancho assassinated. At his coronation, El Cid has Alfonso swear upon the Bible that he had no part in the death of his brother. He swears so, but has Rodrigo banished for his impudence. Jimena’s love for El Cid is rekindled and she is banished with him.
Rodrigo is later called into service of the king once again, to protect Castille from Yusuf’s North African army. He allies himself with the other Emirs who fear Ben Yusuf and at Valencia, Rodrigo relieves the city of the wicked Emir Al-Kadir, who had betrayed him. The Emir Al-Mu’tamin and the Valencians offer the crown to ‘The Cid’, but he refuses it and sends the crown to King Alfonso. Rodrigo then repels the invading army of Ben Yusuf, but is wounded in battle by an arrow before the final victory. If the arrow is removed, there is a chance that he will live, but he will not be able to lead his army. El Cid obtains a promise from Jimena to not remove it, knowing that this will kill him. He intends to ride out, even if dead. King Alfonso comes to his bedside, asks forgiveness and recognizes that he is the noblest knight in all his kingdom.
The morning after El Cid dies, his body is secured upon his horse and sent out at the head of his army with King Alfonso and Emir Al-Mu’tamin on either side of his horse. When Yusuf’s army see him with his eyes still open, they believe that El Cid’s ghost has come back from the dead. Babieca, his horse, tramples on and kills Ben Yusuf, who is too terrified to fight. The invading North African army is completely defeated. The film ends with the Christians and Moors praying and praising the exploit of “El Cid”.