The horse goddess. Rhiannon was the Welsh equivalent of Epona (Gallic) and Macha (Irish). Rhiannon was also associated with a Romano-Celtic goddess Rigantona ("Great Goddess").
Rhiannon was the daughter of Hereydd the Old. She married Pwyll, a chieftain of Dyfed.
Rhiannon was unfortunate figure in Welsh myth. Rhiannon had many suitors, among them were Pwyll, chieftain of Dyfed, and Gwawl, the son of Clud. Pwyll won her hand and married her. Gwawl and his father laid a curse upon Pwyll's household. Rhiannon was barren for many years. Pwyll blamed his wife for their inability to have a child and mistreated Rhiannon.
Even though she managed to give birth to a son named Pryderi, she was falsely accused of killing or devouring her infant.
Later, when Pwyll died, Rhiannon lived with her son before she married Manawyddan, after the death of Manawyddan's brother (Bran) from the war in Ireland. Upon her sons arrival, Rhiannon and Pryderi were beset by curse from Llywd, the son of Kil Coed, and friend of Gwawl, Rhiannon's former suitor. Their subjects in Dyved had vanished. Llywd had transformed Rhiannon into an ass, while her son was transformed into a gate-hammer. They were released from the curses through Manawyddan's cunning and resourcefulness.