The mid 1950s were awash in costume & shining armor romps after the phenomenal success of "Ivanhoe" a few years earlier; some of them were well-written, acted and produced, and others...ah, less so.
Double Feature Torrent! It's "The Black Knight", 1954, starring notorious drunkard Alan Ladd in the waning phase of his career, and "The Black Shield of Falworth", 1954, starring Tony Curtis and his wife (upon whom he was cheating). No, these stars were not quite as virtuous as the characters they portrayed.
I wouldn't dream of telling you which of these is the better movie, but I do suggest watching them in alphabetical order. They're both best enjoyed with tongue firmly in cheek, and a fond appreciation for papier-mâché sets.
Sources & quality: Rescued off eMule where they were lingering after, no doubt, the deaths of their private-site torrents (why do people abandon their children in dark alleys? I can't figure it out). "The Black Knight" was apparently a reasonably good 700mb rip that someone decided to hack the credits off of to make it a little smaller. "The Black Shield of Falworth" is a VHSrip of mediocre quality -- which is about the best it gets short of someone video-capturing an infrequent Turner Movie Classics airing. ***NOTE***: "The Black Shield of Falworth" has _NOT_ been officially released on DVD, and any DVD you see is very likely a crappy VHS transfer no matter how pretty the Photoshopped cover art! You've been warned!