The great-grandson of Cunedda, Maelgwn Hir "Maelgwn the Tall", was one of the most famous (or infamous) leaders in Welsh history.There are several legends about his life concerning miracles performed either by him or in his presence.Undoubtedly a Britonnic leader of substance established himself in North Wales and he and his descendants defeated any remaining Irish presence and incorporated the settlements into their domain and reoriented the whole of Gwynedd into a Romano-British and "Welsh" outlook.The Welsh of Gwynedd remained conscious of their Romano-British heritage, and an affinity with Rome survived long after the Empire retreated from Britain, particularly with the use of Latin in writing and sustaining the Christian religion.All must have seemed lost but Cadwallon raised an enormous army and after a brief time in Guernsey he invaded Dumnonia, relieved the West Welsh who were suffering a Mercian invasion and forced the pagan Penda of Mercia into an alliance against Northumbria.With new vigour Cadwallon returned to his Northumbrian foes, devastated their armies and slaughtered a series of their kings.Rhun returned to Gwynedd, and the rest of his reign was far less eventful. In a rare show of common interest, it appears Gwynedd and neighbouring Kingdom of Powys acted in concert to rebuff the Anglian advance but were defeated at the Battle of Chester in 613.
He was a citizen of Gwynedd and a cousin of Maglos the magistrate".
The unitary kingdom of the Gruffydd ap Llywelyn was shattered by a Saxon invasion in 1063 just prior to the Norman invasion of Wales, but the House of Aberffraw restored by Gruffudd ap Cynan slowly recovered until Llywelyn the Great of Gwynedd was able to proclaim the Principality of Wales at the Aberdyfi in 1216.
That realm lasted until the conquest of Wales by Edward I in 1283.
Early Welsh literature contains a wealth of stories seeking to explain place-names, and doubtless the story is propaganda aimed at justifying the right of Cunedda and his descendants to territories beyond the borders of the original Kingdom of Gwynedd.
That kingdom probably consisted of the two banks of the Menai Straits and the coast over towards the estuary of the river Conwy, the foundations upon which Cunedda's descendants created a more extensive realm.