in the medeival Welsh tales The Mabinogi of Pwyll Prince of Dyfed and The Mabinogi of Manawydan ap Llyr, Rhiannon was a daughter of Hefeydd the Old. Pwyll first met Rhiannon, when she appeared as a beautiful woman dressed in gold and riding a white horse. Pwyll sent his horsemen after her, but she was too fast.

As they were seated, they could see a woman on a large stately pale-white horse, a garment of shining gold brocaded silk about her, making her way along the track which went past the mound. The horse had an even, leisurely pace; and she was drawing level with the mound it seemed to all those who were watching her.