Sir Launcelot is visiting the Queen when Sir Modred and Sir Aggravayne lead the attack to expose them for Adultery.
Arthur orders the queen to be burned for treason. Sir Launcelot comes to rescue her which results in King Arthur declaring war. The pope eventually intervenes and demands the queen be returned to Arthur and Launcelot is banished from England.
Sir Gawain persuades King Arthur to wage war against Sir Launcelot in France. Gawain challenges Launcelot to a joust everyday, until Launcelot accepts. Launcelot repeatedly wins and shows mercy to Gawain.
While Arthur is in France, Sir Modred (his son) makes himself king by faking a letter that Arthur is dead. Arthur comes back and engages in battle with Modred which results in Gawain dying. Gawain's ghost visits Arthur telling him to call a truce or else Arthur will die.
If you do not call a truce with Sir Modred, you will die!
Arthur and Modred try to declare a truce, but a misunderstanding causes another battle. Arthur and Modred kill each other and Arthur is buried in a nearby chapel.
HE DREW HIS SWORD..ATTACK!!!
After hearing about King Arthur's death, Launcelot goes and lives with the Archbishop. After a few years, Queen Gwynevere dies and Arthur buries her next to Arthur. Launcelot dies from sorrow and is buried at Joyous Gard.