The Sword in The Stone by T.H. White, the first book of The Once and Future King, is a novel about a young boy named Wart (for Arthur) who befriends a magician named Merlin. It was published in 1938. The version appearing in 1959 in the tetralogy was substantially revised.

The Walt Disney Company made an animated movie from it in 1961. This movie introduced Mad Madam Mim who later appeared in a lot of Disney comics. The movie is entertaining, but ignores White's carefully-constructed moral lessons in favour of visual gags.

A BBC radio adaptation in 1982 starred Michael Hordern as Merlin. Hordern had already starred as another great literary wizard, Tolkien's Gandalf, in the BBC's Lord of the Rings (1981).