King Pryderi
Pryderi is a fictional character in The Chronicles of Prydain by Lloyd Alexander, very loosely based on the character of the same name in Welsh mythology.
Betrayal
Pryderi appears as a powerful king in The High King, the fifth and final novel of the series. When introduced, he commands nearly half the armies in the western cantrefs of Prydain who are not loyal to the Dark Lord Arawn, the main antagonist of the series. He uses gold as the main color in his clothing and flags, emblazoned with a red hawk. During wartime he wears his sword without a scabbard, symbolizing his resolve to not sheathe his sword until the conflict is resolved. Retainers also carry live hawks when they accompany him on formal occasions.
Pryderi is first referred to as a personal friend of Prince Gwydion of Don, son of Math, King of Prydain, and the addition of his armies to those rallied against the threat of Arawn is eagerly anticipated. However upon reaching Caer Dathyl, the home of the Sons of Don, Pryderi gives Gwydion and his father, the High King Math a very cold greeting. He offers them the chance to surrender their forces to him, or to face him in battle. It becomes clear that he has allied himself with Arawn, believing that the constant petty conflicts between Prydain's minor lords can only be put to a stop under a single ruler strong enough to enforce the peace, and that Arawn is the only one with such strength.
Math and Gwydion both refuse Pryderi's demands and prepare for battle as soon as he leaves. The next morning Pryderi's army attacks the combined army led by Gwydion, Taliesin and Taran, (the main protagonist) outside Caer Dathyl. He is briefly challenged by Taran during the battle, but contemptuously ignores him and sets his own troops between them. As the day draws to a close, Pryderi's army turns to retreat, drawing their heartened foes after them. However, this was a diversion. Pryderi's army parts, allowing a legion of Cauldron-Born led by Huntsman of Annuvin through. The fortress is leveled, and by the next morning both Pryeri and Arawn's troops have withdrawn, completely victorious.
Dallben's prophecy
Pryderi then left his army, taking a squad of nineteen other men with him southward to Caer Dallben. He was sent there by Arawn to kill the mighty enchanter Dallben and to take The Book of Three back to Annuvin, Arawn's Realm of Death. Upon arriving at the farm late at night, Dallben uses his magic to warn away Pryderi's men, but the king presses on and corners Dallben in his room.
Dallben warns him not to come closer, saying that his men were wiser than him for not seeking their deaths. But Pryderi calls him on that, having been told by Arawn that Dallben cannot kill anyone without dying himself. (It is never made clear whether this is true. Dallben admits he has never killed, but denounces Pyderi's "knowledge" as half-truths.) He tries striking down the enchanter with his sword, but the blade breaks on Dallben's staff. He then produces a black dagger, given him by Arawn and bewitched with the power to bypass Dallben's defenses. Dallben admits his disadvantage, but warns that Pryderi will cause his own death by killing the enchanter. Outside, a wall of fire surrounds the farm, ready to immolate everything inside should Dallben be killed. Pryderi suggests the fire will die with the enchanter, but Dallben replies that there is only one way to prove that. Pryderi then states that Arawn would not have sent him to kill Dallben if it meant destroying the Book of Three as well. Dallben's final condemnation of the treacherous king summarizes well his twisted motives:
"You have steeped your hands in blood, and in your pride sought to pass judgement on your fellow men. Was it your concern to serve Prydain? You chose an evil means to do it. Good cannot come from evil. You leagued yourself with Arawn for what you deemed a noble cause. Now you are a prisoner of the very evil you hoped to overcome, prisoner and victim. For in The Book of Three you are already marked for death."
The truth proves too much for Pryderi, who then discards the dagger and grabs at the Book of Three, trying to destroy it. Dallben tries warning him, but as he touches the book, lightning comes from the tome and kills him.