King Ralph (1991) on Netflix

When the entire British Royal family is killed in a freak accident; the search for someone to be the new ruler is undertaken. And they find someone who could be of royal lineage; problem he's an American, Ralph Jones who's a lounge singer. He initially doesn't want any part of it but they convince him to. He then goes and is made King. A Lord who wants his family to be made the rulers and is at the top his family line, doesn't think Ralph is the right choice but parliament gives Ralph a chance. So the Lord plots to make him undesirable. And when Ralph takes a liking to a stripper the Lord thinks he found a way. In the meantime Ralph's staff imposes restrictions on him which makes him think he shouldn't have accepted.