Pwyll expressed his contrition, and, asking the new-comer’s name and rank, offered to atone for his fault. The stranger told his name—Arawn, a king of Annwn—and said that Pwyll could gain his forgiveness only in one way, by going to Annwn instead of him, and fighting for him with Havgan. Pwyll agreed to do this, and the King of Hades put his own semblance upon the mortal prince, so that not a person in Annwn—not even Arawn’s own wife—would know that he was not that king. He led him by a secret path into Annwn, and left him before his castle, charging him to return to the place where they had first met, at the end of a year from that day. On the other hand, Arawn took on Pwyll’s shape, and went to Narberth.
No one in Annwn suspected Pwyll of being anyone else than their king. He spent the year in ruling the realm, in hunting, minstrelsy, and feasting. Both by day and night, he had the company of Arawn’s wife, the most beautiful woman he had ever yet seen, but he refrained from taking advantage of the trust placed in him. At last the day came when he was to meet Havgan in single combat. One blow settled it; for Pwyll, Havgan’s destined conqueror, thrust his antagonist an arm’s and a spear’s length over the crupper of his horse, breaking his shield and armour, and mortally wounding him. Havgan was carried away to die, and Pwyll, in the guise of Arawn, received the submission of the dead king’s subjects, and annexed his realm. Then he went back to Glyn Cûch, to keep his tryst with Arawn.
They retook their own shapes, and each returned to his own kingdom. Pwyll learned that Dyfed had never been ruled so well, or been so prosperous, as during the year just passed. As for the King of Hades, he found his enemy gone, and his domains extended. And when he caressed his wife, she asked him why he did so now, after the lapse of a whole year. So he told her the truth, and they both agreed that they had indeed got a true friend in Pwyll.
After this, the kings of Annwn and Dyfed made their friendship strong between them. From that time forward, says the story, Pwyll was no longer called Prince of Dyfed, but _Pen Annwn_, “the Head of Hades”.
The second mythological incident in the Mabinogi of Pwyll, Prince of Dyfed, tells how the Head of Hades won his wife, Rhiannon, thought by Professor Rhys to have been a goddess either of the dawn or of the moon.[333] There was a mound outside Pwyll’s palace at Narberth which had a magical quality. To anyone who sat upon it there happened one of two things: either he received wounds and blows, or else he saw a wonder. One day, it occurred to Pwyll that he would like to try the experience of the mound. So he went and sat upon it.