The fantasy of royalty mingling among the commoners goes back as far as royalty itself, turning up in classic stories from the Arabian nights to Mark Twain’s Prince and The Pauper to Audrey Hepburn’s Oscar-winning Roman Holiday, and in civilian form, the many runaway heiress films like It Happened One Night.  An urban myth that Queen Elizabeth II and her sister, Princess Margaret celebrated VE Day, the end of the WWII battles in Europe and the surrender of the Nazi forces, by mingling with the crowd, has been turned into a fantasy that the then-teenage princesses had a wild night out on the town. It’s sort of Cinderella in reverse.

King George (played by Rupert Everett and yes, the one from The King’s Speech) and his wife, also called Elizabeth (Emily Watson) are preparing for various ceremonies to recognize the end of the war, including a speech the King is to give on the radio just before the official end of hostilities at midnight. His daughters are the future queen Elizabeth (Sarah Gadon, with an endearing freshness and just a hint of steel), called Lilibet by her family, and the fun-loving Margaret (Bel Powley of “Diary of a Teenage Girl”). Although their father relies on them to be with him when he speaks on the radio, still a very difficult challenge for the man whose stutter was the theme of “The King’s Speech,” they persuade their parents to let them out just once, so they can mingle among the “ordinary people.” Elizabeth has never made a pot of tea, visited a public ladies’ room, or had a drink in a pub, all of which she will get to experience. She has never been spoken to in a familiar manner, and had to be reminded to remove her tiara by a footman who suggests it might rather give her away.

The king and queen think they have outsmarted their daughters by assigning them a military escort and arranging that their outing will be confined to a closed room with carefully selected guests. But the girls escape and are quickly separated. Margaret spends the rest of the night going from one wildly improbable situation to another (including a brothel) while Lilibet searches for her with the help of an RAF airman named Jack (the very appealing Jack Reynor from “Sing Street”), who does not think much of the military or posh people.

Even the most Masterpiece-loving American Anglophiles will find this story lightweight and inside, with some of the accents hard to parse and some of the references obscure. But Gadon, especially in the last half of the movie, is lovely as the girl who grows to enjoy being called Lizzie, and it is satisfying to see her interest in learning about the people who will be her subjects and growing into her power as a woman and a monarch.

Parents should know that this film has drinking, some drug use, some scuffles and fights, sexual references and situations (including prostitutes and a threesome), references to wartime casualties, and some strong language.

Family discussion: If you were a prince or princess, what would you most want to see and experience? Why didn’t Jack want the help of the royal family?

If you like this, try: “Roman Holiday”