Arthur's next move was to send one of his men, Gwrhyr, interpreter of tongues [100], to parley with the boars. Gwrhyr, in the form of a bird, alighted above where Twrch Trwyth and his swine lay, and addressed them as follows: 'For the sake of Him who fashioned you in this shape, if you can speak, I ask one of you to come to converse with Arthur.' Answer was made by one of the boars, called Grugyn Gwrych Ereint, that is, Grugyn Silver-bristle; for like feathers of silver, we are told, were his bristles wherever he went, and whether in woods or on plains, one saw the gleam of his bristles. The following, then, was Grugyn's answer: 'By Him who fashioned us in this shape, we shall not do so, and we shall not converse with Arthur. Enough evil has God done to us when He fashioned us in this shape, without your coming to fight with us.' Gwrhyr replied: 'I tell you that Arthur will fight for the comb, the razor, and the shears that are between the ears of Twrch Trwyth.' 'Until his life has first been taken,' said Grugyn, 'those trinkets shall not be taken, and to-morrow morning we set out hence for Arthur's own country, and all the harm we can, shall we do there.'
The boars accordingly set out for Wales, while Arthur with his host, his horses, and his hounds, on board his ship Prydwen, kept within sight of them. Twrch Trwyth came to land at Porth Clais, a small creek south of St. David's, but Arthur went that night to Mynyw, which seems to have been Menevia or St. David's. The next day Arthur was told that the boars had gone past, and he overtook them killing the herds of Kynnwas Cwrvagyl, after they had destroyed all they could find in Deugledyf, whether man or beast. Then the Twrch went as far as Presseleu, a name which survives in that of Preselly or Precelly, as in Preselly Top and Preselly Mountains in North Pembrokeshire. Arthur and his men began the hunt again, while his warriors were ranged on both sides of the Nyfer or the river Nevern. The Twrch then left the Glen of the Nevern and made his way to Cwm Kerwyn, the name of which survives in that of Moel Cwm Kerwyn, one of the Preselly heights. In the course of the hunt in that district the Twrch killed Arthur's four champions and many of the people of the country. He was next overtaken in a district called Peuliniauc [101] or Peuliniog, which appears to have occupied a central area between the mountains, Llandewi Velfrey, Henllan Amgoed, and Laugharne: it probably covered portions of the parish of Whitland and of that of Llandysilio, the church of which is a little to the north of the railway station of Clyn Derwen on the Great Western line. Leaving Peuliniog for the Laugharne Burrows, he crossed, as it seems, from Ginst Point to Aber Towy or Towy Mouth [102], which at low water are separated mostly by tracts of sand interrupted only by one or two channels of no very considerable width; for Aber Towy would seem to have been a little south-east of St. Ishmael's, on the eastern bank of the Towy. Thence the Twrch makes his way to Glynn Ystu, more correctly perhaps Clyn Ystun, now written Clyn Ystyn [103], the name of a farm between Carmarthen and the junction of the Amman with the Llychwr, more exactly about six miles from that junction and about eight and a half from Carmarthen as the crow flies. The hunt is resumed in the Valley of the Llychwr or Loughor [104], where Grugyn and another young boar, called Llwydawc Gouynnyat [105], committed terrible ravages among the huntsmen. This brought Arthur and his host to the rescue, and Twrch Trwyth, on his part, came to help his boars; but as a tremendous attack was now made on him he moved away, leaving the Llychwr, and making eastwards for Mynyd Amanw, or 'the Mountain of Amman,' for Amanw is plentifully preserved in that neighbourhood in the shortened form of Aman or Amman [106]. On Mynyd Amanw one of his boars was killed, but he is not distinguished by any proper name: he is simply called a banw, 'a young boar.' The Twrch was again hard pressed, and lost another called Twrch Llawin. Then a third of the swine is killed, called Gwys, whereupon Twrch Trwyth went to Dyffryn Amanw, or the Vale of Amman, where he lost a banw and a benwic, a 'boar' and a 'sow.' All this evidently takes place in the same district, and Mynyd Amanw was, if not Bryn Amman, probably one of the mountains to the south or south-east of the river Amman, so that Dyffryn Amanw may have been what is still called Dyffryn Amman, or the Valley of the Amman from Bryn Amman to where the river Amman falls into the Llychwr.