Rivallo () was a legendary king of the

Britons British people or Britons, also known colloquially as Brits, are the citizens of the United Kingdom, the British Overseas Territories, and the Crown dependencies.: British nationality law governs modern British citizenship and nationality, w ...

as accounted by

Geoffrey of Monmouth Geoffrey of Monmouth (; ; ) was a Catholic cleric from Monmouth, Wales, and one of the major figures in the development of British historiography and the popularity of tales of King Arthur. He is best known for his chronicle '' The History of ...

. He came to power in 817BC.Monarchie Nobelesse website, ''Bretons''
/ref> He was the son of King

Cunedagius Cunedagius ( Latinized form; ) was a legendary king of the Britons, as recounted by Geoffrey of Monmouth. He came to power in 850BC. He was the son of Henwin, Duke of Cornwall, and Regan, the daughter of King Leir. Cunedagius, grandson of Le ...

and was noted as a young king who reigned with moderation. Geoffrey describes him as a "peaceful and fortunate youth, who ruled the kingdom well".Geoffrey of Monmouth: The History of the Kings of Britain : an Edition and Translation of De Gestis Britonum (Historia Regum Britanniae), Boydell & Brewer, 1 Jan 2007, p.44. His reign was troubled by natural disasters: a rain of blood that lasted three days, a devastating plague, and a great swarm of flies. He was succeeded by his son Gurgustius.

References

{{Geoffrey of Monmouth Legendary British kings