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 Merlyn. It was published in 1938.
The version appearing in 1959 in the tetralogy was substantially revised, partly to incorporate events and themes that White had originally intended to cover in a fifth volume (which was finally published after his death, as The Book of Merlyn). To this end, the revised version includes several new sequences and leaves out some of the sequences that had appeared in the original (notably the sequence that was the basis of the Mad Madam Mim scenes in the Disney film).
The Walt Disney Company made an animated movie version of The Sword in the Stone, first released on December 25, 1963. Like most Disney films, it is based on the general plot of the original story, but much of the substance of the story is considerably changed.
A BBC radio adaptation in 1982 starred Michael Hordern as Merlyn. Hordern had already starred as another great literary wizard, Tolkien's Gandalf, in the BBC's Lord of the Rings (1981).