MGM's first CinemaScope production was the lavishly appointed Knights of the Round Table. Without overlapping into any copyrighted material (specifically T.H. White's The Once and Future King), the film spins a lucid account of the King Arthur legend. The good king is played by Mel Ferrer, while Queen Guenevere is essayed by Ava Gardner. Arthur's efforts to create a perfect society in Camelot are compromised when Guenevere falls in love with trusted knight Sir Lancelot (Robert Taylor). The ambitious Mordred (Stanley Baker) uses his knowledge of the Queen's indiscretion to destroy both Camelot and King Arthur's round table. Most of the story material in Knights of the Round Table is lifted from Sir Thomas Malory's Le Morte D'Arthur.
~ Hal Erickson, All Movie Guide