Annowre (Anouwre) is an evil enchantress who desires King Arthur in Thomas Malory's Le Morte d'Arthur. Malory based her on a character from the earlier Prose Tristan, who was named as Elergia in the Italian La Tavola Ritonda.
As told by Thomas Malory, Lady Annowre was a great sorceress from North Wales (Norgalles), who fell in love with King Arthur and tried to seduce him when he came to Cardiff. But when she could not get Arthur to lie down and make love to her even by the means of magic, as he would remain faithful to Guinevere no matter what, she plotted his death.
Lady Annowre entices Arthur to her tower in the heart of the Perilous Forest (Forest Perilous), where every day he is forced to fight for his life. The Lady of the Lake, Nimue (Nineve, Nyneve, etc.), learns of this peril. She finds Tristan (Tristram) and brings him to the tower where they arrive just in time to see two knights defeat Arthur. As Annowre is about to decapitate the king using his own sword, Tristan rushes in and kills her knights. Nimue shouts to Arthur not to let Annowre escape, and the king chases down the sorceress and unceremoniously beheads her with the same sword (in some versions, it is Tristan who cuts her head off. Nimue then hangs Annowre's head by the hair to her saddle as a symbol of victory.