When a freak accident wipes out an entire royal family an exhaustive search reveals a distant relation: Ralph Jones (Goodman) a good-natured down-to-earth Las Vegas entertainer. Immediately the rude and crude Ralph is given a crash course in royal manners by his new private secretary the very proper Lord Willingham (Peter O'Toole). But while Ralph's uncouth behavior delights the public it fuels a fiendish plot by the evil Lord Graves (John Hurt) who's out to oust the new ruler. Now it's up to this lowborn lounge singer to redeem himself in a manner befitting a king in this warmhearted comedy romp.