LAUNCELOT du Lake returns from Rome most honored of all Arthur's knights and therefore most prized by the queen. He decides to seek knightly adventures, presumably to win still greater renown. He rides out with his nephew Sir Lionel and in the heat of noon goes to sleep under an apple tree. Lionel, keeping watch, sees a powerful knight overwhelm and tie up three weaker knights. When Lionel tries to help them he too is bound and carried back to the castle of the wicked Tarquin, where all four captives are stripped naked, beaten with thorns, and thrown into a dungeon. Ector, who has followed Launcelot and Lionel, is also caught.
While Launcelot is asleep under the tree, Morgan le Fay and three other ladies find him and fall in love with him. Morgan returns him to her castle by enchantment, and there the four ladies demand that he choose one of them or die. Launcelot refuses to choose any lady, and is saved by a maiden in return for his promise to help her father, Sir Bagdemagus, in his tournament.
Launcelot rides through a forest, finds a pavilion, and lies down to rest. A knight comes, mistakes his sleeping form for that of his lady, and lies down beside him. They fight, and Launcelot wounds the knight. The expected lady arrives and asks Launcelot to use his influence to make her knight one of the Round Table. Launcelot agrees.
The next morning he goes to the abbey where he is to meet Sir Bagdemagus. He wins the tournament for Sir Bagdemagus, then leaves to hunt for his nephew.
