Note 30 — Chapter IX · Place-name Stories

We find them next at Ỻwch Tawi, the position of which is indicated by that of Ynys Pen Ỻwch, ‘Pool’s End Isle,’ some distance lower down the Tawe than Pont ar Dawe. At this point the boars separate, and Grugyn goes away to Din Tywi, ‘Towy Fort,’ an unidentified position somewhere on the Towy, possibly Grongar Hill near Ỻandeilo, and thence to a place in Keredigion where he was killed, namely, Garth Grugyn. I have not yet been able to identify the spot, though it must have once had a castle, as we read of a castle called Garthgrugyn being strengthened by Maelgwn Vychan in the year 1242: the Bruts locate it in Keredigion30, but this part of the story is obscured by careless copying on the part of the scribe31 of the Red Book. After Grugyn’s death we read of Ỻwydawc having made his way to Ystrad Yw, and, after inflicting slaughter on several of his assailants, he is himself killed there. Now Ystrad Yw, which our mapsters would have us call Ystrad Wy, as if it had been on the Wye32, is supposed to have covered till Henry VIII’s time the same area approximately as the hundred of Crickhowel has since, namely, the parishes of (1) Crickhowel, (2) Ỻanbedr Ystrad Yw with Patrishow, (3) Ỻanfihangel Cwm Du with Tretower and Penmyarth, (4) Ỻangattock with Ỻangenny, (5) Ỻaneỻy with Brynmawr, and (6) Ỻangynidr. Of these Ỻanbedr perpetuates the name of Ystrad Yw, although it is situated near the junction of the Greater and Lesser Grwynë and not in the Strath of the Yw, which Ystrad Yw means. So one can only treat Lanbedr Ystrad Yw as meaning that particular Ỻanbedr or St. Peter’s Church which belongs to the district comprehensively called Ystrad Yw. Now if one glances at the Red Book list of cantreds and cymwds, dating in the latter part of the fourteenth century, one will find Ystrad Yw and Cruc Howel existing as separate cymwds. So we have to look for the former in the direction of the parish of Cwm Du; and on going back to the Taxatio of Pope Nicholas IV dating about 1291, we find that practically we have to identify with Cwm Du a name Stratden’, p. 273a, which one is probably to treat as Strat d’Eue33 or some similar Norman spelling; for most of the other parishes of the district are mentioned by the names which they still bear. That is not all; for from Cwm Du a tributary of the Usk called the Rhiangoỻ comes down and receives at Tretower the waters of a smaller stream called the Yw. The land on both sides of that Yw burn forms the ystrad or strath of which we are in quest. The chief source of this water is called Ỻygad Yw, and gives its name to a house of some pretensions bearing an inscription showing that it was built in its present form about the middle of the seventeenth century by a member of the Gunter family well known in the history of the county. Near the house stands a yew tree on the boundary line of the garden, and close to its trunk, but at a lower level, is a spring of bubbling water: this is Ỻygad Yw, ‘the Eye of the Yw.’ For Ỻygad Yw is a succinct expression for the source of the Yw burn34, and the stream retains the name Yw to its fall into the Rhiangoỻ; but besides the spring of Llygad Yw it has several other similar sources in the fields near the house. There is nothing, however, in this brook to account for the name of Ystrad Yw having been extended to an important district; but if one traces its short course one will at once guess the explanation. For a few fields below Ỻygad Yw is the hamlet of the Gaer or fortress, consisting of four farm houses called the Upper, Middle, and Lower Gaer, and Pen y Gaer: through this hamlet of the Gaer flows the Yw. These, and more especially Pen y Gaer, are supposed to have been the site of a Roman camp of considerable importance, and close by it the Yw is supposed to have been crossed by the Roman road proceeding towards Brecon35. The camp in the Strath of the Yw was the head quarters of the ruling power in the district, and hence the application of the name of Ystrad Yw to a wider area. But for our story one has to regard the name as confined to the land about the Yw burn, or at most to a somewhat larger portion of the parish of Cwm Du, to which the Yw and Tretower belong. The position of the Gaer in Ystrad Yw at the foot of the Bwlch or the gap in the difficult mountain spur stretching down towards the Usk is more likely to have been selected by the Romans than by any of the Celtic inhabitants, whose works are to be found on several of the neighbouring hills, such as Myarth36 between the Yw and the Usk.