As Lancelot, Nicholas Clay strikes a handsome figure, unlike the less-than-perfect Lancelot of The Ill-Made Knight. Both Boorman and White, however, stress Lancelot's absence from the Round Table as a means for him to avoid his own desires; as White remarks in The Ill-Made Knight, Lancelot's quests "were his struggles to save his honor, not to establish it." Lancelot's longing for Guenever is repeatedly shown to the viewer through many shots of his pining away in the forest, looking out at the castle where his true love dwells; Guenever eventually meets Lancelot in the forest to consummate their affair. This pastoral paradise is toppled, however, by Arthur's discovery of them, naked and asleep in a grove. He raises Excalibur — but rather than sinking it into Lancelot's heart, he plunges the sword into the earth. When the lovers awake they know exactly Arthur's message: "The king without a sword," Lancelot exclaims. "The land without a king!" Boorman implies that Lancelot and Guenever's betrayal of Arthur has opened wide the door for evil to enter Camelot — and it is at this point in the film that Morgana seduces her brother by transforming herself into the likeness of Guenever. Her using the same spell as Uther used to lie with her mother suggests the truth of what Merlin remarks early in the film: "It is the doom of men that they forget." Deception, like history, repeats itself.
Mordred is as sarcastic and spoiled in Excalibur as he is in The Ill-Made Knight and The Candle in the Wind. Born during a thunderstorm while his mother labors under the pain of her own evil, he is next shown as a giggling and malicious boy who leads Perceval to a tree where Arthur's other knights hang from nooses, with birds pecking at their faces. As a young man, he threatens his father, who is weakened from the collapse of his kingdom and the inability of his knights to find the Grail, with revolution. His father's plea, "I cannot give you the land — only my love" is met with, "That's the one thing of yours I don't want!" In White's novels, Mordred's evil is somewhat explained by the novelist's portrayal of Morgause, whose demanding yet distant nature makes her sons go to terrible extremes to win her approval; Boorman's Mordred is motivated by his quest for power. One of the only things the viewer hears him say to his mother is, "When will I be king?"
