The Mabinogion is a collection of great Welsh tales and legends. The extant manuscripts date back to the thirteenth century, but their style and content indicate an earlier origin, possibly up to two hundred years earlier. The stories are all about members of the Welsh royal family and their households, but as embodiments of the ancient gods and goddesses of the land.
There are four main branches:
Pwyll Prince of Dyfed
Branwen The Daughter of Llyr
Manawyddan The Son of Llyr
Math The Son of Mathonwy
and other associated tales (depending on the version) including The Lady of the Fountain, Geraint and Enid, and the tale of Taliesin.