Note 21 — Chapter VI · The Folklore of the Wells
Reading edition
These are not all the questions which such stories suggest; for Seithennin is represented in later Welsh literature as the son of one Seithyn, associated with Dyfed; and the name Seithyn leads off to the coast of Brittany. For I learn from a paper by the late M. le Men, in the Revue Archéologique for 1872 (xxiii. 52), that the Île de Sein is called in Breton Enez-Sun, in which Sun is a dialectic shortening of Sizun, which is also met with as Seidhun. That being so, one would seem to be right in regarding Sizun as nearly related to our Seithyn. That is not all—the tradition reminds one of the Welsh legend: M. le Men refers to the Vie du P. Maunoir by Boschet (Paris, 1697) p. 126, and adds that, in his own time, the road ending on the Pointe du Raz opposite the Île de Sein passed ‘pour être l’ancien chemin qui conduisait à la ville d’Is (Kaer-a-Is, la ville de la partie basse).’ It is my own experience, that nobody can go about much in Brittany without hearing over and over again about the submerged city of Is. There is no doubt that we have in these names distant echoes of an inundation story, once widely current in both Britains and perhaps also in Ireland. With regard to Wales we have an indication to that effect in the fact, that Gwyđno, to whom the inundated region is treated as having belonged, is associated not only with Cardigan Bay, but also with the coast of North Wales, especially the part of it situated between Bangor and Ỻandudno21. Adjoining it is supposed to lie submerged a once fertile district called Tyno Helig, a legend about which will come under notice later. This brings the inundation story nearer to the coast where Ptolemy in the second century located the Harbour of the Setantii, about the mouth of the river Ribble, and in their name we seem to have some sort of a historical basis for that of the drunken Seithennin22. I cannot close these remarks better than by appending what Professor Boyd Dawkins has recently said with regard to the sea between Britain and Ireland:—