RIVALLO

'Rivallo' (''Welsh:'' 'Rriallon') was a legendary king of the Britons as accounted by Geoffrey of Monmouth. He was the son of King Cunedagius and was noted as a young king who reigned frugally. Various sources list conflicting dates for his reign: 811–765 BC (see House of Cornwall), 815–797 BC [1], and 767–743 BC [2]. He is recorded as the misplaced king of Domnonée [3].
His reign was troubled by disasters. He was noted as being remembered for a rain of blood which lasted three days, a devastating plague, and a great swarm of flies [4]. Despite these problems, he was remembered as king who ruled wisely. He was succeeded by his son, Gurgustius.