King Arthur is the protagonist of The Once and Future King and the novel’s narrative and emotional center. The novel follows Arthur’s life from beginning to end, and the major events in his life shape the story. After Arthur becomes king, his ideas about government reshape English society, and these changes determine the plot, chronology, and setting of the four books that make up the novel. Even the novel’s title promises that although the story ends with Arthur’s death, he will always be England’s ruler. Despite Arthur’s extraordinary importance to the novel, however, he is a fairly simple character. As a child, Arthur (then called the Wart) is honest, trusting, modest, and good-hearted, and he preserves these qualities when he becomes king. King Arthur shapes his government with an important new philosophy that makes him a great king, but the ideas are Merlyn’s rather than Arthur’s. Arthur is exceptional because he believes in these ideas and is able to enact them when he becomes king.

Arthur develops a sense of world-weariness and wisdom in the novel’s later books, but this development is gradual and his basic nature is not drastically altered. Benevolent optimism keeps Arthur from acknowledging Lancelot and Guenever’s love affair early in the novel; later, the same benevolence causes him to persuade them to keep their behavior secret. Even as he grows older and wiser, Arthur is incapable of acting harshly toward the people he loves, no matter how hurtfully they treat him. In a sense, it is Arthur’s very simplicity and earnestness that enables the downfall of his reign. While the direct cause of the tragedy is Arthur’s incestuous affair with Morgause, we do get a sense that Camelot is also doomed because it has stagnated. The energy and progress of Arthur’s early reign slows to a halt, and Arthur becomes a defender of the status quo. This lack of innovation sets in around the time that Nimue imprisons Merlyn, suggesting that Arthur cannot think and develop without his old tutor. It is as though Arthur can only ride the momentum of his earlier ideas without forming any new ones. As Camelot stagnates and the quest for the Holy Grail takes its toll on the Knights of the Round Table, the Orkney faction is able to gain more power, until Camelot is too corrupt to survive.

Lancelot is the protagonist of Book III and the greatest knight in the company of the Round Table. He is Arthur’s best friend and a powerful foil for the king since he is complex and full of contradictions. Lancelot is also Arthur’s opposite in that, while he is always able to take swift and decisive action, he is rarely able to use this ability to make the world a better place. Even when Lancelot performs a heroic deed, he does so accidentally, not because he has heroic ideals or good intentions. Lancelot’s ugliness gives him a sense of unworthiness and inadequacy from a very young age, but this low self-esteem is paired with an astonishing, almost unnatural talent for all knightly skills and endeavors. The ease with which Lancelot wins glory as a knight, combined with his gnawing sense of inferiority, is the source of most of his contradictions. Lancelot is both religious and lustful, both hideous and exalted, both meek and violent. He is simultaneously Arthur’s best friend and betrayer.

Lancelot is a prisoner of such contradictions. His own complexity keeps him from growing as a person, since he is too humble to exalt in his success and allow it to improve his self-image. Cutting through all of these contradictions is Lancelot’s unyielding, passionate love for Guenever; ultimately, their affair becomes both the best and the worst thing to happen to him. Lancelot’s love for Guenever provides Lancelot with moments of bliss but also compounds his guilt and leads to his downfall.

Queen Guenever is the third figure in the love triangle that dominates the novel’s second half. She is also the least developed of the novel’s central triad, which is consistent with White’s tendency to focus on male characters. White often stereotypically describes women as being girlish or needy, like Elaine, or as cruel vamps, like Morgause. Unlike Arthur and Lancelot, Guenever does not seem to have any particularly remarkable qualities that mark her as a great or noteworthy queen. She is beautiful, but she is also jealous, selfish, petty, and shallow. Guenever is capable of love, and she loves Arthur as genuinely as she loves Lancelot, though not as passionately. While Lancelot’s guilt about their affair reaches epic proportions and threatens to destroy him, any guilt Guenever feels is secondary to her constant craving to be with Lancelot. She even handles their cover-up badly, and at one point she is visibly excited to be reunited with Lancelot even in front of Arthur. As Guenever ages, she tries desperately to stay young and beautiful, as her pathetic attempts to cover her flaws with too much makeup demonstrate. In the novel’s third book, “The Ill-Made Knight,” White writes that it is “difficult to imagine” Guenever, and this difficulty translates to her role in the novel. She is a central character, but she is important more for the way others feel about her than for anything she herself does or feels.