In Geoffrey of Monmouth's Historia regum Britanniae, a fictional account of the rulers of Britain, Dionotus was a legendary King of the Britons during the campaigns in Gaul led by Emperor Magnus Maximus. The curious thing about this king's that the Welsh chronicles, which parallel most of Monmouth's book, doesn't mention this king by name. He succeeded his brother, Caradocus as ruler of the Britons and Cornwall. Nothing's said of Dionotus until he became king under Maximus. He's first mentioned… (More on Dionotus)