Manawyddan, besides being the principal hero in one of the Mabinogi, is the subject of two Triads, in one of which his singular adventures are thus alluded to:-
"Three Makers of Golden Shoes, of the Isle of Britain: Caswallawn the son of Beli, when he went as far as Gascony to obtain Flur, the daughter of Mygnach Gorr, who had been carried thither to Caesar the Emperor, by one called Mwrchan the Thief, king of that country and friend of Julius Caesar, and Caswallawn brought her back to the Isle of Britain; Manawyddan the son of Llyr Liediaith, when he was as far as Dyved laying restrictions; Llew Llaw Gyffes, when he was along with Gwydion, the son of Don, seeking a name and arms from Arianrod, his mother."In the other, he is represented as one of the humble princes of the Island. Having become a bard after the captivity of his brother Bran, he did not afterwards resume his rank, although he might have done so.
Manawyddan is mentioned in the Dialogue between Arthur, Kai, and Glewlwyd; and his name occurs in connection with that of Pryderi in the poem on the Sons of Llyr, "Kerdd meib Llyr," of Taliesin.
