Rhufoniog was a small sub-kingdom of the Dark Ages Gwynedd

Kingdom of Gwynedd

Gwynedd was one petty kingdom of several Welsh successor states which emerged in 5th-century post-Roman Britain in the Early Middle Ages, and later evolved into a principality during the High Middle Ages. It was based on the former Brythonic tribal lands of the Ordovices, Gangani, and the...

, and later a cantref in medieval Wales

Wales

Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

. According to tradition, it was ruled by its eponymous founder Rhufon, the third son of the first King of Gwynedd, Cunedda

Cunedda

Cunedda ap Edern , was an important early Welsh leader, and the progenitor of the royal dynasty of Gwynedd.-Background and life:The name Cunedda derives from the Brythonic word , meaning good hound. His genealogy is traced back to Padarn Beisrudd, which literally translates as Paternus of the...

, and his direct descendants from the year 445 until the year 540 when it was probably absorbed back into direct control of Gwynedd proper.