Sean Scully appears as both prince and pauper in the same scenes using the same split-screen method employed in The Parent Trap (1961).
The historical Edward VI who the Prince represents lived from 1537-1553 sadly dying of illness at 15. He was crowned at the age of nine. Fully aware of his fate, he named his cousin Lady Jane Grey, who we see in the film, as his successor. However his sister Mary deposed Lady Grey nine days after her coronation.
Jane Asher, seen here as future "Nine Days Queen" Jane Grey, would play Tudor queen consort Jane Seymour - the mother of Prince Edward - in Henry VIII and His Six Wives (1972).
Originally broadcast in the UK in 1961 on the Magical World of Disney and in the US on NBC in three parts in March of 1962.