Glamorgan

Geoffrey of Monmouth says that Cundahʹ and Morgan, the sons of Gonorill and Regan, usurped the crown at the death of Cordeilla. The former resolved to reign alone, chased Morgan into Wales, and slew him at the foot of a hill, hence called Gla-Morgan or Glyn-Morgan, valley of Morgan. (See Spenser: Faërie Queene, ii. 10.)