Rhiannon first appears at Gorsedd Arberth, an ancestral mound near one of the chief courts of Dyfed. Pwyll, the prince of Dyfed, has accepted the challenge of the mound's magical tradition to show a marvel or deal out blows. Rhiannon appears to him and his court as the promised marvel. She is a beautiful woman arrayed in gold silk brocade, riding a shining white horse. Pwyll sends his best horsemen after her two days running, but she always remains ahead of them, though her horse never does more than amble. On the third day he finally follows her himself and does no better, until he finally appeals to her to stop for him.