As an odd note, in his parody novels of 19th Century British history, the author George McDonald Fraser used his antihero Sir Harry Flashman in a more fleshed out version of The Prisoner of Zenda, in his novel Royal Flash.
Fraser’s novels were noted for their fairly close approximation of the rather outrageous times of the British Empire in that period, along with many of the world’s real villains and scoundrels they contended with.
The first in the series, titled just Flashman, is an extraordinarily good history of the fall of British Afghanistan. It is bawdy, treacherous, cowardly, and features perhaps the worst military commander in history, General Elphinstone, who turned retreat into a terrible disaster. With of course, Flashman smack in the middle of things.
I loved the Flashman novels. They were extremely accurate. Royal Flash was one of my least favorites, as it was so heavily derived from Zenda. The film version Royal Flash was pretty good, IMO. I though Malcolm McDowell made a splendid Flashy.