The British turned out many historical films, including those based on classical novels. And, U. K. filmmakers made some sterling comedies, some of which could rival the best of the Hollywood Golden Era. But I don't recall there being many historical comedies until later in the 20th century. Well, "Cardboard Cavalier" of 1949 is an exception and clearly has some fun with history, including quite a bit of twisting it.
Overall, this film isn't exceptional or very good. But, it is light-hearted, has a silly and sometime far out plot, and it does have some nice shots of humor here and there. Those are almost always around Sid Field's character, Sidcup Buttermeadow. Indeed, except for the obvious historical figures, the choice of names for the fictional people is part of the British humor that I especially appreciate in such films. Some others, beside Field's character are Judge Gorebucket by Miles Malleson, Brother Barebones by Michael Brennan, Sylvester Clutterbuck by Claude Hulbert, and Mosspot by Peter Bull.
Well this whole thing takes place during that nagging interruption of the regal reigns of England - of whatever branch of monarchy, It was during the English civil wars and George Cromwell's reign of the md 17th century. Buttermeadow becomes a courier for the loyalists to the king, and in the end, he's celebrated for helping the cause for King Charles's return. A humorous bit that historians and anglophiles especially should enjoy, is the inclusion of the legendary Nell Gwynn. Margaret Lockwood plays the most famous of a baker's dozen of mistresses of Charles. But in this film, she's admired by the throngs as the actress and consort of Charles, even riding in the parade of the king's return.
This isn't a great laugh fest for viewers, but a pleasant and fun film to watch as the cast (and crew) poke friendly jabs at history. This was one of only two films that the very popular stage show entertainer Sid Field made. That earned it one more star from me.