The Castilian tells the story of the legend of Fernan Gonzalez who led the first successful resistance to the Moslem Moors in 10th century Spain. For the American audiences and the only actors who did not need English dubbing, Cesar Romero, Broderick Crawford, and Frankie Avalon are in the cast.
I kid you not, Frankie Avalon. The then teenage idol is a minstrel who sings a few songs accompanying himself on the lute and does the narration. He does look kind of cute in his minstrel boy outfit, although voices like Orson Welles or Alexander Scourby are normally used for the role of narrator in epics. But Frankie sings real nice.
The role of Fernan Gonzalez is played Espartaco Santoni who had a fairly decent career in the Spanish cinema according his list of credits here. He's was no threat to Charlton Heston though.
As history and the story line of the film have it, Castile would not have been a betting man's choice as the place that would eventually take over and unite the various turfs that made up Spain. It was a small county caught between two bigger Christian kingdoms, Leon and Navarre, and to the south by the Moors. Everybody wants to be top dog.
Allegedly the patron saint of Spain, the disciple James and the patron saint of Castile, Milan long dead were sighted riding in battle against the Moors. That's shown here in the film and for sincere believers it is part of the record.
The film was shot at the actual battle locations, no doubt with the great cooperation of the Franco government which never missed an opportunity to emphasize Spain's Catholic tradition. On the other hand, financing was on the cheap, El Cid was done a whole lot better.
