Guiderius (Welsh Gwydr), according to the traditional British history found in Geoffrey of Monmouth's Historia Regum Britanniae (History of the Kings of Britain) and related texts, was the eldest son of Cymbeline, and succeeded his father to the kingship of Britain. He can probably be identified with the historical Togodumnus. Welsh redirects here, and this article describes the Welsh language. ... Geoffrey of Monmouth was a clergyman and one of the major figures in the development of British history. ... Geoffrey of Monmouths Historia Regum Britanniæ (English: The History of the Kings of Britain) was written around 1136. ... Cunobelinus (also written Kynobellinus, Cunobelin) was a historical king of the Catuvellauni tribe of pre-Roman Britain. ... Togodumnus was a historical king of the British Catuvellauni tribe at the time of the Roman conquest. ...

Cymbeline had voluntarily paid tribute to Rome, but Guiderius refused to pay it. The emperor Claudius responded by invading. Claudius with his chief of staff, Lelius Hamo, landed at Portchester, entrenching themselves there while besieging the city. Guiderius conscripted all the men of Britain against Claudius and marched south to meet him in battle. The Britons clashed with the Romans and succeeded so well that the Roman army began retreating to their ships. Ancient Rome was a civilization that existed in Europe, North Africa, and the Middle East between 753 BC and its downfall in AD 476. ... Roman Emperor is the title historians use to refer to rulers of the Roman Empire, after the epoch conventionally named the Roman Republic. ... A statue of Emperor Claudius Tiberius Claudius Nero Caesar Drusus (August 1, 10 BC–October 13, 54), originally known as Tiberius Claudius Drusus Nero Germanicus, was the fourth Roman Emperor of the Julio-Claudian dynasty, ruling from January 24, 41 to his death in 54. ... Location within the British Isles. ...

Hamo, though, took on Briton armour and began attacking his own army, urging the Britons to do likewise. Because of this, Hamo was able to get close enough to Guiderius to strike him. Guiderius died then or soon after and was succeeded by his brother Arvirargus, who took over as king during that battle. Arvirargus was a legendary king of the Britons as accounted by Geoffrey of Monmouth. ...

Cunobelinus (also written Kynobellinus, Cunobelin) was a historical king of the Catuvellauni tribe of pre-Roman Britain. ... The term King of the Britons refers to kings of Celtic Great Britain as recorded by much later authors, including Nennius, Gildas, and predominantly Geoffrey of Monmouth. ... Arvirargus was a legendary king of the Britons as accounted by Geoffrey of Monmouth. ...