Welsh: Great Queen
Daughter of Hevedd Hen, possibly an otherworld being, and wife of Pwyll pen Annwfn. She was also mother to Pryderi and later wife to Manawyddan ap Llyr.
She is accused of Pryderi's murder when he disappers as an infant. She is innocent, however, and much of her life is led trying to rescue Pryderi from the trouble he gets himself in.
She is often identified as a horse goddess, equivalent to the Gaulic Epona and the Irish Macha. She also has three magic birds, the Birds of Rhiannon, whose song no man can resist.
She is an aspect of Modron the Welsh mother goddess.