Prisoner of Zenda (1988)

Children's animation, comedy-adventure, very loosely based on the classic swashbuckler. 1902: When old King Wilhelm of Ruritania is dying, he has to choose which of his two sons is to succeed him. He chooses Prince Rudolf - much to the annoyance of Prince Michael, who immediately starts scheming... Meanwhile, a Ruritanian princess spots the new king's double, Rudolf Rassendyll, at a ball in London. Rassendyll travels to Ruritania, and finds himself not only having to stand in for King Rudolf, but also to rescue him from the dungeons of the castle of Zenda.