Morgan le Fay is, in Mallory's Morte d'Arthur, Arthur's half sister, the daughter of Arthur's mother Ygraine and her first husband, the Duke of Cornwall. She is also presented as an adversary of Arthur's: she gives Excalibur to her lover Accolon so he can use it against Arthur and, when that plot fails, she steals the scabbard of Excalibur which protects Arthur and throws it into a lake. She is presented as the instigator of the Green Knight's visit to Arthur's court, partly motivated by her desire to frighten Guinevere whom she hates due to Guenivere's interference in Morgan's affair with Guiomar, Guenivere's cousin.  Morgan is also said to be the wife of King Uriens and the mother of Yvain or Ywain. Urien was assassinated during a military campaign around 590.  In late life she moved to the Isle of morganlefay, and it was to here that she and her allies, the Queens of Northgalis (North Wales) and the Wastelands, took her wounded brother to be healed after the Battle of Camlann.