Matunus Stone, High Rochester
My identification of Arthur with Cerdic of Wessex and then with Ceredig son of Cunedda naturally led me to a consideration of the Arthur name. Ceredig, I discovered, had three descendants with Art- or "Bear" names. This seemed promising, but I at first could not account for why bears were so important among the early members of this princely line. Then I turned to the geography of their kingdom in western Wales, viz. Ceredigion. There I noticed a river called the Arth - literally, the Bear River - in the very heartland of the region over which they ruled.
Afon Arth in Ceredigion
I went on to surmise that the name Arthur, indisputably from the Roman/Latin Artorius, was a decknamen that had replaced an earlier Irish or Hiberno-British 'bear-king' title or name. As Ceredig was the founder of the kingdom, he would have been the first of his line to be given a bear designation. Aerial archaeology has only recently found what is believed to be a hillfort at Llandewi Aberarth and this defensive work may well have been built or re-used by Ceredig.
Having established all this (at least in theory!), my next question had to do with the nature of the original 'Bear-king' name/title. Was this merely a territorial honorific, one which did no more than identify Ceredig as the King of the Arth [River]? Or was some totemic element present? The Aeron River hard by the Arth is from a Proto-Celtic *Agrona, meaning 'Carnage-goddess'. Divine rivers are plentiful in Celtic lands and Wales is no exception. Several examples are known. Might the Arth, too, have been a divine stream? And, if so, was it worshiped by Ceredig/Arthur?
Well, it goes without saying these questions cannot be answered definitively. Bears were sacred animals among the Celtic peoples prior to the coming of Christianity. Of this we have sufficient evidence. I'm posting below several scholarly treatments of Celtic bear worship. Some are converted pdfs and, alas, lack the images once embedded in the texts. Some problems also occurred with information arranged in columns. Hopefully, the vast majority of the material is readable.
My main problem with Arthur/Ceredig being a pagan has to do precisely with his decknamen Artorius. Such Latin names were assumed because the chieftain in question wished to be perceived as a civilized Briton who looked back upon the Roman period with nostalgic longing. Connections with famous Romans of the past were constantly being sought and genealogies forced to reflect family relationships with such Romans. The Romans of the later period were, of course, thoroughly Christian. Hence it makes little sense to propose pagan worship of a divine Bear River by a Bear-king of Ceredigion who had taken a Roman name!
Furthermore, Irish sources insists Cunedda himself was a saint. While this sainthood could well have been bestowed on Ceredig's father only by later and, possibly, spurious tradition, it is true that Ireland itself became fully Christian fairly early on. We must consider the possibility, then, that when Cunedda and his sons (or teulu) came over to Wales they were already Christian.
I long ago identified Caer Dathal with Dindaethwy on Anglesey. From my book THE MYSTERIES OF AVALON:
Daethwy is preserved in the place-names Porth-(D) aethwy and Dindaethwy on Anglesey. Dathal is an Irish name, from dath, ‘swift, nimble, quick’, and is also found in another form, Dathi, or Daithi in the genitive. If Dathi/Daithi could in some cases be a hypocorism of Dathal, then Caer Dathyl would be but another name for Din Daethwy, the ‘Fort of the Territory/Center of the Tribe of Dathi/Daith’. In Welsh, the -wy suffix denotes a region belonging to a tribe named after their founder or progenitor (see Melville Richards' "Early Welsh Territorial Suffixes").
As it happens, the region of Dindaethwy has within it a significant hill-fort called Din Sylwy or BWRDD ARTHUR, the Table of Arthur. The etymology for Sylwy of Din Sylwy is not difficult, as we have the early forms Dinsillu (1254) and Dinsylow (1291/2) in the Melville Richards Place-Names Archives. These spellings show the –wy to be a late development, the originally meaning of the name being ‘Fort with a View’. Such a purely descriptive name allows us to opt for Din Daethwy/Caer Dathal as its earlier designation, especially as there is no other fort in the hundred of Din Daethwy.
Although said to be in Arfon, Din Silwy just across the Menai Strait from Arfon is the best candidate for Caer Dathal.
Din Sylwy or Bwrdd Arthur
On the name Mathonwy, from Rachel Bronwich's TRIADS:
The problem with traditional stories like 'Culhwch and Olwen' is that they are manifestly works of fiction. In all likelihood someone arbitrarily associated Arthur with the Welsh word for bear ('arth') and then decided to link him with the inhabitants of Math's Caer Dathal for no other reason than Math was also known to denote a bear. Thus we cannot point to a bear god Math or Mathon in Anglesey and in any way relate him historically to Arthur of the Bear River in Ceredigion.
But as Ceredig and his father came from Ireland, might there have been a legendary Irish bear hero who may have inspired or influenced the bear worship of the princes of Ceredigion?
Indeed there might. Most students of early Irish history (or heroic mythology) are familiar with the king Art ("Bear") son of Conn. This 2nd century high-king of Ireland was famous in story (http://www.maryjones.us/ctexts/art.html). But more importantly, he is brought into close connection with one Tadg son of Cian. And Cian is the eponymous founder of the Ciannachta, to whom Cunedda belonged.
"Ciannachta Breagh and Fir Arda Cianachta
The annals record for 226, Cormac mac Art, king of Ireland, defeated the Ulster forces under Fearghus Duibhdeadach with the assistance of Tadg (or Teige), son of Cian. For this service the king bestowed on Tadg a large territory in Magh Breagh which extended from the Liffey (in Dublin) northwards to Drumskin in Co. Louth. Tadg's descendants were called Cianachta, "the race of Cian", from his father and the territory was afterwards known by this name. The sons of Tadgc mac Céin (of the 3rd century) were Condla (a quo Ciannacht) and Cormac Gaileng (a quo Sil Cormaic Gaileng). The ancient territory of Fir Ard Cianachta in modern co. Louth became known as the barony of Ferrard."
Could Art son of Conn, the great benefactor of Tadg son of Cian, have somehow been brought into connection with the Afon Arth? Should the bear-names in the Ceredigion genealogy be seen in this light?
Lastly, we should consider the etymologies for the three remaining bear-names in the Ceredigion royal pedigree. Artbodgu or Arthfoddw is 'Bear-Crow'. While the name may seem odd, we must remember that Artbodgu's father was Bodgu, making Artbodgu the 'Bear of the Crow.' Artgloys or Arthlwys is 'Beautiful or Holy Bear' and Arthgen (perhaps the most interesting of them all!) is 'Bear-Born' or 'Born of the Bear.' Arthgen's father is named Seissil. Is Arthgen's human mother here being referred to as a bear? Bear in Welsh poetic usage can be a metaphor for a warrior, so we cannot always be sure that a bear-name necessarily derives from an association with the sacred river. Still, the most logical explanation for Arthgen is that he was thought of as being born from the mother goddess that was the Afon Arth.
In the nebulous period following the Roman withdrawal from Britain, religion was surely not so black and white as we would like to think it was. There must have been an admixture of pagan and Christian among some individuals and groups. The worship of Christ and a sacred river may not, for awhile at least, have been seen as mutually exclusive. We have instances of pagan gods and goddesses being 'converted' into Christian saints, of churches being built atop temples, of pagan holy wells being co-opted by their Christian successors. Folk beliefs are often a curious amalgam of the supposedly extirpated pagan religion and Christian practice. Pagan myths or, at least, motifs, were faithfully copied and preserved by Christian scribes. Ancient Celtic tales were transmogrified by troubadours and writers into chivalric romance. Given that all this is demonstrably true, perhaps it is not too difficult to provisionally accept the idea that Arthur and his bear-named descendants had, indeed, worshiped the Afon Arth.