Chimene (Sophia Loren) is the centerpiece of the Spanish camp. All the major men characters focus on her. (As does Alfonso's snarky sister, who appears both jealous and in awe of Chimene.)Note that both her father and her husband, at the moment of their deaths, cry out for Chimene. Both plead for her to follow their wishes afterward. After losing a battle to Ben Yussuf, it's to Chimene that King Alfonso flees. It's to her that he seeks to prove his courage. ("It takes more to be a king than courage," she tells him.) Alfonso imprisons her, holding her and her children as hostage to get the Cid to do his bidding. Rodrigo is about to abandon the siege of Valencia to go after her-- until she's freed by the Raf Vallone character, Ordonez, who lives only for her. She is the dominating personality of the narrative.
At the outset of the story, Alfonso is the weakest of the two princes, dominated by his sister Uracca (ably played by Genevieve Page). As the movie progresses he struggles to match the model Rodrigo sets for him. Rodrigo and Chimene have what seems to us absurd self-discipline-- which the weak king seeks to adopt. They are his antagonists but at the same time his role models. At the end he overcomes his preening self-involvment to join the Cid for the final battle. He's able to step into the Cid's spot.
THE RELIGIOUS CONFLICT
"El Cid" gives the viewer a great deal to consider: namely, the nature of the two great faiths whose clash is at the heart of the story. From the desert comes the primal Islamic faith in its purest version, or so Ben Yussuf assures us. Contrasted with this is the historic Islam known for its great intellectual and cultural accomplishments. Which is the genuine Islam? The pampered emirs appear unable to challenge Yussuf's voice of authority.
On the other side, remember that European Christianity was always a pagan-Christian hybrid. The Spanish knights have adopted the trappings of the religion, but remain in their behavior thoroughly Visigoths. Rodrigo's break with them comes when he begins behaving like a Christian, to the extent of forgiving his enemies after defeating them. He's not sure himself why he does so-- it happens after he encounters a burned-down church. Those he ends up forgiving include the Moor Moutamain; Ordonez; and Alfonso himself-- all who eventually come to his side. Rodrigo of course is the strongest knight, but also the farthest-seeing and most honorable.
I hope I've shown that this is a complex movie-- deeper in its themes than most films have been, yet the themes are well-blended to be inseparable from the artistry of sound and image and the momentum of the narrative. The Big Questions are addressed, including fate and destiny, how to live, life and death. Yet wait-- there's more to talk about.