The major character of The Once and Future King is Arthur, whom Merlyn affectionately nicknames "Wart." One of the strengths of White's novel is that it keeps its focus on Arthur; in many versions of the Arthurian legend, the major emphasis falls on Lancelot and Guenever.

White does not portray Arthur as an all-powerful legendary hero but as a good, honest person, not very clever but willing to work hard to understand the lessons Merlyn teaches him. This is most obvious in The Sword in the Stone, where Merlyn changes Wart into different animals so that the boy can learn the ways of nature. Even after Merlyn departs, Arthur must struggle in order to rule justly and keep the kingdom at peace.

Arthur's chief flaw, which helps to bring on his downfall, is his excessive goodheartedness. This trait makes him unwilling to acknowledge evil...