Beau Brummell is another of those movies that impressed me a lot when I was a kid. It's one of those big, lavish MGM Technicolor productions that's (very) loosely based on a true story. If you want history, you'll have to watch something else, though. The movie's not historically accurate at all and doesn't care to be. It's entertainment.
Peter Ustinov is the weakling Prince of Wales. Stewart Granger is the unbending Beau Brummell, who becomes the prince regent's unlikely friend and tries to make him into a man worthy of the crown. Elizabeth Taylor is the beautiful love interest who has to choose between the excitement and danger of Brummell and the security that someone more stable can offer. Brummell is something of a con man and rascal, but his affection for the Prince is real. The story of Brummell's rise and fall is carried off with wit and style, and the ending is [SPOILER] a real tear-jerker.
I've heard that Beau Brummell was a flop on its original release. I don't know why, but maybe the fact that it was bit of a downer had something to do with it. I liked it then, when I liked downers, and I like it now when I usually don't like them. Check it out and see what you think.