If I'm not mistaken, that is broadly when the Arthur stories were "updated". (We do have a copy of Mort d'Arthur, but I can't remember off hand where it is and I'm too idle to look for it.)
A Knight's Tale isn't trying to use Chaucer and the Black Prince as historical characters, they are, as you say, simply "props" in the dressing up that is the film.
Re: A Knight's Tale
If I'm not mistaken, that is broadly when the Arthur stories were "updated". (We do have a copy of Mort d'Arthur, but I can't remember off hand where it is and I'm too idle to look for it.)
A Knight's Tale isn't trying to use Chaucer and the Black Prince as historical characters, they are, as you say, simply "props" in the dressing up that is the film.