The leader of the family who kept charge of the Grail, called the Fisher King by some writers, but sometimes given as a separate ruler.
In Wolfram, the succession of Grail Kings is given as Titurel, Frimutel, Anfortas, Perceval, and Loherangrin; in the Vulgate romances, they are Joshua (a follower of Joseph of Arimathea), Aminadap (Aminabad), Carcelois, Manuel, Lambor, Pellehan, and Pelles.
Sometimes the Grail King is the same as, or becomes, the Maimed King. The Grail King ruled the Grail Kingdom from the Grail Castle.
Parzival | Wolfram von Eschenbach, 1200–1210
Vulgate Queste del Saint Graal | 1215-1230
Vulgate Estoire del Saint Graal | 1220-1235