The play focuses on Don Rodrigue and Chimène. Rodrigue's father, Don Diègue, is the old upstart general of Kingdom of Castile and past his prime, whereas Chimène's father is the successful current general, Comte de Gormas. Rodrigue and Chimène love each other, but any chance of marriage is brutally disturbed when Chimène's father insults Rodrigue's father. Torn between his love for Chimène and his duty to avenge his father's honour, Rodrigue chooses the latter and faces the general in a duel in which Don Gormas is killed. Without denying her love, Chimène asks the King for Rodrigue's head.
When the Moors attack, Rodrigue gets the chance to redeem himself in the eye of the nation, and, more importantly, gets a chance to win back Chimène with honour still satisfied. His victories on the battlefield win him the renown of the people, the title of "the Cid", and the gratitude of the King.