Four descriptions of Sir Lancelot in "The Lady of Shalott" depict him as the quintessential knight in shining armor. His shield, his baldric, his face, and his speech align him with the knight's code of chivalry (see link). The shield Lancelot uses is decorated with a "red-cross knight [who] forever kneeled to a lady," showing that he stands for the knightly value of respecting the honor of women. His baldric, which is a belt worn diagonally from shoulder to opposite hip and that could carry a bugle or sword, is "blazoned," that is, decorated with heraldic symbols. Heraldry was a system of design that indicated which line of knights a warrior was from; it might indicate a family line, region of a country, or both. This shows Lancelot to be part of the brotherhood of knights, dedicated to the rule of the chivalric code that requires him to protect the honor of his fellow knights.

With his "broad clear brow" that glows in the sunlight, the poet implies that Lancelot is honest, that he "eschew(ed) unfairness, meanness and deceit" and that he would "at all times speak the truth," according to the code of chivalry. Finally, when Lancelot speaks at the end of the poem, he reveals his Christian faith by blessing the lady, saying, "God in his mercy lend her grace." This shows he is dedicated to the first rule of knighthood, namely, "to fear God and maintain His Church." Certainly that he bothers to make a statement over the mysterious woman's corpse suggests that he is interested in protecting the weak and defenseless, also part of the knight's code.

The ending scene recalls the previous description of the lady as having "no loyal knight and true." Understanding the code of chivalry as embodied in Sir Lancelot elucidates how keenly the lady would have felt that lack.