Greetings!
Ivanhoe
Starring: Robert Taylor, Elizabeth Taylor, Joan Fontaine, George Sanders, Emlyn Williams
Directors: Joseph Barbera, Richard Thorpe, and William Hanna.
MGM Studios, 1952.
Based on the original book, "Ivanhoe" by Sir Walter Scott
Knights of the Round Table
Starring: Robert Taylor, Ava Gardner, Mel Ferrer, Johnny Green, Anne Crawford
Directors: Richard Thorpe
MGM Studios, 1953
Based on Thomas Mallory's 14th century epic story.
El Cid
Starring: Charlton Heston, Sophia Loren, Raf Vallone
Director: Anthony Mann
1961
The film is based on the hero, El Cid, from the 11th century, focused on the efforts of the Spanish to free Spain from the Muslim Moors.
I also recommend the 1979 film, Excalibur. Just edit the brief sex scenes, and it's a fine movie. I saw it when I was 12 though, and it was fine. The brief sex scene is a bit alluring, for sure, especially to a 12 year old boy, but it isn't especially graphic.
As good character-studies, I also recommend many of the famous Westerns starring John Wayne. Many of them are good, and span his career from the 1930's to the 1970's. While westerns are a different genre than medieval, John Wayne often speaks and demonstrates beahvior and attitudes appropriate for a good paladin throughout many of these films. In addition, many of John Wayne's World War II films also do a good job of this as well.
Semper Fidelis,
SHARK