Two entries with the name Queen of Orkney.
Queen of Orkney
The sister of Adalon and the lord of the Narrow Borderland.
Queen of Orkney
Mother of Agravain, Gareth, Gaheris, Gawaine, and their half-brother Mordred.
She had an affair with Lamorat, son of Pellinore, an enemy of the family. When they were discovered, Gaheris killed his mother and his brothers slew Lamorat.
See also
Margawse of Orkney | The Legend of King Arthur
Morchades | The Legend of King Arthur
Sources
Post-Vulgate Suite du Merlin | 1230-1240
Prose Tristan | 1230-1240