The reasons White made the last revisions are open to speculation. Publishers have tended to carry on using the original versions when they were published independently of the tetralogy the original, American, and 'Once and Future King' versions are still in print. Some critics considered the revised version to be inferior to the original. It leaves out some of the episodes that had appeared in the original (notably Merlyn's battle with Madam Mim which appeared in the Disney film). To this end, the revised version includes several new episodes, including a pacifist passage in which Arthur is transformed into a wild goose that flies so high as to not be able to perceive national boundaries. The version appearing in 1958 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). The English Collins first edition was partially rewritten for Putnam in America. However it makes no attempt at consistent historical accuracy, and incorporates some obvious anachronisms (aided by the concept that Merlyn lives backwards in time rather than forwards, unlike everyone else). The setting is loosely based on Medieval England, and in places it incorporates White's considerable knowledge of medieval culture (as in relation to hunting, falconry and jousting). He also has more human adventures, at one point meeting the outlaw Robin Hood (who is referred to in the novel as Robin Wood). Merlyn magically turns Wart into various animals at times. The premise is that Arthur's youth, not dealt with in Malory, was a time when he was tutored by Merlyn to prepare him for the use of power and royal life.

Sword in the stone novel