Pwyll (“Good Judgment”), lord of Dyfed, is out hunting one day when he insults another hunter who is, in fact, King Arawn of the “Otherworld” (Annwn), the land of re-birth from which on October 31/November 1 (Christian All Saints and All Souls Days and later Halloween—derived from All Hallows’ Eve, Hallows being “saints”) souls can return to the world and take vengeance on offenders. Pwyll drives off Arawn’s hounds and substitutes one of his own in pursuit of a stag. Furious, Arawn demands that Pwyll wear his—Arawn’s—face for a year and live as king in Annwn for that time. He is to sleep in the Otherworld king’s bed, but must promise not to make love with his wife.

When the punishment period is over, Pwyll returns to Dyfed and holds a great feast. Soon after he takes his place on his throne, a beautiful woman rides by on a white horse and Pwyll pursues her, begging her to stop. After a fruitless chase of the woman, Pwyll begs her to stop, which she does. The woman is the goddess Rhiannon, daughter of Arawn; she offers herself as Pwyll’s wife. Rhiannon has possible cognates in the Irish goddesses Edain Echraide (“horse riding”) and Macha, who outran horses, and in the Continental Celtic horse goddess, Epona. All these figures have roots in earlier Indo-European horse-based myths and rituals. During their wedding feast Pwyll loses his wife to Gwawl (“light”) as a result of a foolish granting of a wish. He wins her back, however, at Rhiannon and Gwawl’s wedding, by tricking his rival into entering a magic bag given to him by Rhiannon.