The name Cunedda (spelled Cunedag in the AD 828 pseudo-history Historia Brittonum) derives from the Brythonic word *Cunodagos, meaning good hound. His genealogy is traced back to a grandfather named Padarn Beisrudd, which literally translates as Paternus of the "red tunic". One traditional interpretation identifies Padarn as a Roman (or Romano-British) official of reasonably high rank who had been placed in command of Votadini troops stationed in the Clackmannanshire region of Scotland in the 380s or earlier by the Emperor Magnus Maximus. Alternatively, he may have been a frontier chieftain who was granted Roman military rank, a practice attested elsewhere along the empire's borders at the time. In all likelihood, Padarn's command in Scotland was assumed after his death by his son, Edern (Latin: Æturnus), and then passed to Edern's son, Cunedda.
According to Old Welsh tradition contained in section 62 the Historia Brittonum, Cunedda came from Manaw Gododdin, the modern Clackmannanshire region of Scotland:
Maelgwn, the great king, was reigning among the Britons in the region of Gwynedd, for his ancestor, Cunedag, with his sons, whose number was eight, had come previously from the northern part, that is from the region which is called Manaw Gododdin, one hundred and forty-six years before Maelgwn reigned. And with great slaughter they drove out from those regions the Scotti who never returned again to inhabit them.
Cunedda and his forebears led the Votadini against Pictish and Irish incursions south of Hadrian's Wall. Sometime after this, the Votadini troops under Cunedda relocated to North Wales to defend the region from Irish invasion, specifically the Uí Liatháin, as mentioned in the Historia Brittonum. Cunedda established himself in Wales, in the territory of the Venedoti, which would become the centre of the kingdom of Gwynedd. Two explanations for these actions have been suggested: either Cunedda was acting under the orders of Maximus (or Maximus's successors) or Vortigern, the high king of the British in the immediate post-Roman era. The range of dates (suggested by Peter Bartrum) runs from the late 370s, which would favour Maximus, to the late 440s, which would favour Vortigern.
The suggestion that Cunedda was operating under instructions from Rome has been challenged by several historians. David Dumville dismisses the whole concept of transplanting foederati from Scotland to Wales in this manner, given that the political state of sub-Roman Britain would probably have made it impossible to exercise such centralised control by the 5th century. As Maximus himself was dead by the end of 388, and Constantine III departed from Britain with the last of Rome's military forces in 407, less than a generation later, it is doubtful that Rome had much direct influence over the military actions of the Votadini, either through Maximus or any other emissary, for any significant length of time.
Maximus (or his successors) may have handed over control of the British frontiers to local chieftains at an earlier date; with the evacuation of the fort at Chester (which Mike Ashley, incidentally, argues is most likely where Cunedda established his initial base in the region, some years later) in the 370s, he may have had little option. Given that the archaeological record demonstrates Irish settlement on the Llŷn Peninsula however and possible raids as far west as Wroxeter by the late 4th century, it is difficult to conceive of either Roman or allied British forces having presented an effective defence in Wales.
Academics such as Sheppard Frere have argued that it may have been Vortigern who, adopting elements of Roman statecraft, moved the Votadini south, just as he invited Saxon settlers to protect other parts of the island. According to this version of events, Vortigern would have instructed Cunedda and his Votadini subjects to move to Wales in response to the aforementioned Irish incursions no later than the year 442, when Vortigern's former Saxon allies rebelled against his rule.
Cunedda's supposed great grandson Maelgwn Gwynedd was a contemporary of Gildas, and according to the Annales Cambriae died in 547. The reliability of early Welsh genealogies is not uncontested however, and many of the claims regarding the number and identity of Cunedda's heirs did not surface until as late as the 10th century. Nonetheless, if we accept this information as valid, calculating back from this date suggests the mid-5th-century interpretation.
Of Cunedda personally even less is known. Probably celebrated for his strength, courage, and ability to rally the beleaguered Romano-British forces of the region, he eventually secured a politically advantageous marriage to Gwawl, daughter of Coel Hen, the Romano-British ruler of Eboracum (modern York), and is claimed to have had nine sons. The early kingdoms of Ceredigion and Meirionnydd were supposedly named after his two sons Ceredig and Meirion.
The hill of Allt Cunedda close to Cydweli in Carmarthenshire is probably associated with this Cunedda and suggests his campaigns against the Irish extended from Gwynedd into to south west Wales. Amateur excavations of this site in the 19th century revealed an Iron Age hill fort and several collapsed stone cists containing the buried but well preserved skeletons of several men with formidable physical proportions. At least one of these was found in the seated position and another buried beneath a massive stone "shield" who had apparently been killed by a head wound. The bones appear to have been sent to various museums and have all since been woefully lost. One of the tumuli was known locally as Banc Benisel and was reputedly the grave of a Sawyl Penuchel, a legendary King of the Britons presumably from late Iron Age Britain. His epithet Penuchel or Ben Uchel means "high head" perhaps on account of his height.  According to the Welsh Life of Saint Cadoc, a king named Sawyl Penuchel held court at Allt Cunedda. Confusingly, Geoffrey of Monmouth, in his Historia Regum Britanniae (1136), uses the name Samuil Penessil for a legendary pre-Roman king of Britain, preceded by Redechius and succeeded by Pir. Whether this is the same king and Cadoc's tale is just revisiting an old folk memory, this a different man of the same name, or simply an error by the composer of the Life, is unclear.
Much of the archaeological evidence was inadvertently destroyed by J. Fenton's expedition in 1851 and it is not known if all the great men buried at this site were contemporaries or if there were successive burials on a site with long term cultural significance. The name connection with Cunedda makes it tempting to speculate that the great Cunedda himself may have been buried at this site; a site whose Iron Age notoriety may well have maintained a cultural importance well after the end of the Roman period and into the Dark Ages. The folk memories of people living near Allt Cunedda that were recorded by the Victorian antiquarians suggests an enduring respect for this site of deep historic importance.Eternus (Edeyrn) father
Paternus (Padarn Beisrudd, of the red robe) grandfather
Tacitus (Tegid) great grandfather
Enniaun Girt (Einion Yrth)