: pri-DER-ee or PRI-der-ee
Welsh: anxiety, care. From "pryder"
Pryderi ap Pwyll
1. The center of the Four Branches of the Mabinogi, found in the first four tales of The Mabinogion.
The son of Pwyll and Rhiannon, he was stolen from his parents when an infant, and was found in a barn, surrounded by horses, on Walpurgisnact (April 30/Beltane Eve/May Eve) by Terynon, who named him Gwri Golden Hair. The boy grew at twice the normal rate, and when a bit older, Terynon realized that this was the missing son of Pwyll and Rhiannon, at which point he was returned to court and named "Pryderi." He married Cigfa, and took over the land when his father presumably died. At this point, he is also left in charge of his father's magic swine from Annwfn.
Pryderi was also part of the party that tried to rescue Branwen from her cruel husband, and thus witnessed the devistation caused by the Cauldron of Rebirth. He is one of the Seven survivors of Prydein. On returning to Dyfed, he sits on Gorsedd Arberth, causing the land to become a Waste Land. He then foolishly chases after a golden bowl, and is imprisioned by his father's enemy Llwyd, only to be set free by his new stepfather Manawyddan. This also restores the waste land of Dyfed, and Pryderi and Cigfa can go home. Now Pryderi takes up the swine of Annwfn. At this point, Gwydion tries first to buy them with fake money, and when caught, kills Pryderi in a magic duel.
The figure of Pryderi is an incarnation of the god Mabon ap Modron/Maponos, the god of light, music, and healing in Celtic culture. His story, seen in light of Mabon's, can also be compared to that of Perceval, in his naivete, his association with magic vessels, and the Gorsedd Arberth (a precursor of the Seige Perilous).
There is some confusion as to who his father was. While the text says Pwyll, there is also evidence that he is possibly son of Teyrnon--"teyrnon" is derived from Tigernonos means "Great Prince," and "rhiannon" is derived from Rigantona--"great queen." There is also some question as to whether his father is originally Manawyddan, who does later become his stepfather. If Manawyddan is his real father, then Bran, the Fisher King, is his uncle--and this links the figure of Pryderi to Perceval.
2. The one-time ally and then adversary of Gwydion in The Chronicles of Prydain by Lloyd Alexander. He is killed by touching the Book of Three.