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Gwydion ap Dôn, a MythSource painting
Welsh

Gwydion ap Dôn

01Identity

Gwydion ap Dôn in Welsh tradition

News of unfamiliar swine in the south brings Gwydion before Math. In Lady Charlotte Guest’s 1877 English Mabinogion, Gwydion names Pryderi as their owner and says Arawn sent the animals from Annwn. Math reminds Pryderi that he had earlier refused to part with them but allows a trade. Gwydion offers what appears to be a valuable display of gifts; the goods are made from fungus. Pryderi and his counsellors accept, and Gwydion leaves with the swine. When armed hosts pursue them, he leads his men towards Gwynedd. They pen the animals at Arllechwedd before continuing to Math at Caerdathyl, where opposition across the country is growing. Later Gwydion and Pryderi arm themselves and fight. Gwydion’s magic helps him prevail. Pryderi is killed and buried at Maen Tyriawc above Melenryd.

SourceThe Mabinogion (Lady Charlotte Guest translation, 1877): Math, the Son of Mathonwy, p. 414· The Mabinogion (Lady Charlotte Guest translation, 1877): Math, the Son of Mathonwy, pp. 415–416· The Mabinogion (Lady Charlotte Guest translation, 1877): Math, the Son of Mathonwy, p. 417· The Mabinogion (Lady Charlotte Guest translation, 1877): Math, the Son of Mathonwy, p. 418

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02The myths

The myths of Gwydion ap Dôn

1 myth, with sources recorded for each.

Gwydion's swine deception and conflict with Pryderi

Gwydion brought Math news of unfamiliar swine in the south. Math asked who owned them. Gwydion named Pryderi, saying Arawn had sent the animals from Annwn. Math recalled that Pryderi had refused to sell or give the swine away, but allowed him to exchange them. Gwydion proposed a trade and presented an impressive display of gifts. Pryderi and his counsellors agreed. The offered riches were made of fungus, and Gwydion departed with the swine instead.

Gwydion warned his men that groups were gathering to pursue them and led them towards Gwynedd’s fastnesses. They travelled to the highest town of Arllechwedd and made a pen for the animals. Then they continued to Math at Caerdathyl, while resistance gathered across the country. Later, Gwydion and Pryderi came out armed and fought. Gwydion prevailed through magic. Pryderi died; his grave was at Maen Tyriawc above Melenryd.

Gwydion's swine deception and conflict with Pryderi, a MythSource painting of the scene

4 sources· checked 2026-09-28

  1. 1The Mabinogion (Lady Charlotte Guest translation, 1877)T1
  2. 2The Mabinogion (Lady Charlotte Guest translation, 1877)T1
  3. 3The Mabinogion (Lady Charlotte Guest translation, 1877)T1
  4. 4The Mabinogion (Lady Charlotte Guest translation, 1877)T1