The Castle of Tears, owned by the parents of Lord Galehaut, stood on the island, and Tristan had to conquer it in order to leave the island. In the Prose Tristan, it is called the Giantís Isle. The "Wicked Custom" was that the visiting knightís lady would be compared to the paramour of the islandís lord. Whichever was least beautiful was beheaded.
Lancelot called himself the Wicked Knight after his five years of insanity.
Chevalier Malfait | The Legend of King Arthur
Island of Joy | The Legend of King Arthur
The knight Alban called himself the Wicked Knight. He challenged Lancelot and was defeated.
The name of a horn blown by one of Sir Parsamantís servants in order to summon people to a fight between Parsamant and another knight.
Parsamantís treatment of defeated knights was wicked, and Perceval finally ended his custom.