Ceneu was an early King of Northern Britain, the heir of Coel Hen (the Old). His Kingdom stretched from Coast to Coast. Ceneu appears to have been canonized because he upheld the old Christian ways while under intense pressure from invading pagans. High-King Vortigern's policy of employing Saxon mercenaries to defeat British enemies meant that, for most of his reign, Ceneu was obliged to accept the help of the Saxons, Octha and Ebissa, in pushing back invading Picts from his kingdom. Their interference was widely resented and it was not until after the Kentish rebellion that they were finally brought under control. Magnanimous in victory, Ceneu allowed the Saxons to settle in Deywr (Deira - East Yorkshire). Ceneu appears in Geoffrey of Monmouth's History of the Kings of Britain as having attended the coronation of the great King Arthur. if so, he must have lived to an extreme old age. Upon his death, Ceneu's kingdom was divided between his two sons, Gwrast and Mor.
Gwrast took the western lands stretching from the Salway to the Mersey, while Mor inherited the central kingdom around the old capital, Ebrauc (York).