Gwynn ap Nudd is regarded as the king of the Tylwyth Teg, the fairies of Welsh lore and the leader of the Welsh Wild Hunt.
According to Culhwch and Olwen, Culhwch was a great and famous noble warrior and also part of the hunt for the great boar Twrch Trwyth. Gwyn and Gwythyr also set out with Arthur to retrieve the blood of Orddu, witch of the uplands of hell . He also abducted Creiddylad from Gwythyr and created havoc in the family. After the intervention of Arthur, Gwyn and Gwythyr fab Greidawl agreed to fight for Creiddylad each Calan Mai [May Day] until Judgement Day. The warrior who will be victorious on this final day would at last take the maiden.
Gwynn ap Nudd become later a mysterious figure who gathers on the battlefields the souls of fallen British warriors, such as Bran the Blessed, Meurig ap Carreian, Gwendoleu ap Ceidaw and Llacheu ab Arthur.
Gwynn ap Nudd role as a psychopomp is paralleled in his later tradition as leader of the Wild Hunt (like Woden or Herne the Hunter), in which he leads a pack of supernatural hounds known as the Cŵn Annwn to harvest human souls.
In Welsh folklore, to hear the baying of Gwyn’s hounds is a portent of imminent death in the family. Some traditions name Gwyn’s chief huntsman as Iolo ap Huw, who, every Halloween, “may be found cheering Cŵn Annwn over Cader Idris”.
As commonly noted, the name Gwyn ap Nudd is related to that of Fionn mac Cumhaill, who is descended from Nuadu (Airgetlám or Necht). T. F. O’Rahilly speculated (1946) that both Gwyn and Fionn are identical with the divine hero Lug Lámfhota.
- Gwyn ap Nudd is the title of one of the most notable poems of the Welsh writer H. Elfed Lewis (1860–1953).
- Idris L. Foster, ‘Gwynn ap Nudd’, in Duanaire Finn, iii, ed. Gerard Murphy, Irish Texts Society, no. 43 (Dublin, 1953), 198–205; Jenny Rowland, Early Welsh Saga Poetry (Cambridge, 1990).