In her notes on the Mabinogion, Lady Guest states the following in regards to Pryderi: -
"Pryderi (care or anxiety), is frequently alluded to by the Bards, who speak of him under either name indiscriminately. In the Mabinogi of Kilhwch and Olwen, he appears under his earlier appellation. However, Pryderi is that by which he is best known. He was one of the chief swineherds of the island, and was so called because he kept the swine of Pendaran Dyved, in the Vale of Cuch in Emlyn. One of the Triads says that the swine he tended were those of Pwyll himself, and that he had the care of them during his father's absence in Annwn. This version, however, does not correspond with the circumstances as given in the text,which imply that Pryderi's birth must have taken place long after Pwyll's mysterious expedition."Pryderi's later years are detailed in the Mabinogi of Manawyddan, with whom his name is coupled in a passage of the 'Kerdd am Veib Llyr', attributed to Taliesin.
In the tale of Math ab Mathonwy, it is related that Pryderi was deprived of life by Gwydion ab Don, who was enabled by magic to overcome him in single combat, after having by similar means defrauded him of some swine which had been sent him from Annwn. The encounter took place near Melenryd, a ford on the Cynvael, a river of Merionethshire. The same authority places his grave at Maen Tyriawg, near Ffestiniog, but a different locality is assigned to it in the Englynion Beddau.
"In Abergenoli is the grave of Pryderi,
Where the waves beat against the shore."
