Character Analysis
This French knight is Arthur's right-hand man… and also the illicit lover of his not-so-blushing bride. He's also the Bestest Knight Ever, and can really bring it when it comes to jousting and tournaments. Few knights want to take him on, and even when he's in disguise, most people can recognize him by his smooth riding. He's just that good at the whole knightly thing. He's also good-good. He tries to be nice to people, and can't stand to entertain petty thoughts for too long (K.4.44).
He's also, unfortunately, been beaten about the head and neck with the fabled ugly stick. For one thing, his ears stick out dreadfully. He's also compared to "an African ape" and is apparently "as ugly as a monster in the king's menagerie" (K.1.24). Poor Lancelot. Guenever even tells him at one point to leave and to take his ugly face with him. What a switcheroo from how Lancelot is usually described in Arthurian romance: as a hottie.
From the time he's a little boy, Lancelot just knows he's going to be a great knight. He's already got his Nom de Knight picked out: Le Chevalier Mal Fet. This is French for (you guessed it), The Ill-Made Knight. We find out later that this has a plethora of meanings—all of which totally work for this guy: The Ugly Knight; The Ill-Fated Knight; The Knight Who Has Done Wrong; and The Knight with a Curse on Him.
Bestie and Bae
Lancelot's relationship status is "It's Complicated." He's got himself into a real pickle, because he's both best friends with King Arthur, but also Guennie's bae. This drags on for many, many years, and becomes a sort of open secret in the court.
For the most part, Lance and Guen keep it pretty secret, but the cat's almost out of the bag when Sir Meliagrance accuses Guen of cheating on the King. Lancelot's forced to basically murder the poor guy to keep their secret on lockdown.
The situation with Guen is made even more complicated by his relationship with Elaine. You see, Elaine seduced him because he's just that hot and she was totally in love with him. She becomes pregnant with his kid, who ends up being Galahad, who is the one knight that can best Lance.
The Elaine issue causes lots of entertaining drama with Guenever. His spats with Guen cause Lance to go crazy (and we're not talking metaphorically—he goes legit crazy. Did we forget to mention that madness runs in his family? Well, it does), and he runs around as a naked Wild Man for a while.
He's always got Guen and Arthur's back, though, and he's constantly riding in to save the day. Except when the secret gets out because of Agravaine and Mordred's jealousy, and he's forced to fight a war against his best bro.
This Bad Boy Wants to Do Good
Lance kind of has that whole bad boy thing going on. He's a bit of a sadist; he likes to hurt people. In fact, that's how he falls in love with Guen. He hurts her feelings over her mistake when they're out hawking, and in that moment he recognizes her as a real person. His sadistic streak is what makes him so super-conscious of hurting others, so he's extra good to make up for it. He's always merciful to foes, and tries not to hurt other people's feelings… but he totally likes it when he does.
In fact, he wants to be so good that he'll be able to perform miracles. This is his greatest wish when he's a little boy, and we're told that he was "a very holy little boy" (K.14.36). He believes that (kind of like Samson) his strength comes from his purity. So he's totally angry when Elaine dupes him into losing his V-card with her (by tricking him into believing she's actually Guenever, whoops). And once he's no longer a virgin, he figures, like Jack in Titanic, "If you got nothing, you got nothing to lose," and ends up right in Guenever's bed.
Turns out, Lance is able to do miracles. He does, after all, save Elaine from that perpetual pot of boiling water. And he heals Sir Urre. But, he really beats himself up good when he's unable to achieve the Holy Grail—and he blames it on his sexual relationship with Guenever.
Because of this, he is only able to see a partial glimpse of the Grail, and is hailed as the best of "earthly, sinful" men (K.33.28). We get this really pathetic picture of Lancelot in his Grail Quest, "plodding along behind these three supernatural virgins [Galahad, Percivale, and Bors]" and "his doomed, courageous, vain toil" (K.33.28).
In the end, he's brought down by his own goodness in a way. Because he, himself, doesn't have it in him to be treacherous, he can't imagine that anyone else would be treacherous, so he doesn't believe Bors when he warns him that Agravaine and Mordred are strategizing to bring him down.