Houses of Dôn and Llyr
The family tree below displays two important families in Welsh mythology: the Children of Llyr and the Children of Don. There were conflicts between the two houses during the reigns of Math in the north and Pryderi in the south of Wales.
The House of Llyr was represented by Bran and Manawyddan, and they were allied with Pwyll and his son Pryderi, the lords of Dyved, a kingdom in southern Wales. Bran was king of the whole of Britain. Manawyddan married Pwyll's widow Rhiannon.
The family of the House of Don had a kingdom in northern Wales called Gwynedd. They were ruled by Don's brother, Math. The tale about this northern family was mostly about Don's children and her grandson Lleu. Don's own daughter Penarddun was married to Llyr, and was the mother of Bran, Branwen and Manawyddan.
The tales about these families are told in the first four tales of the Mabinogion, which was often called the Four Branches of the Mabinogi. See the Mabinogion to read the four tales.
Family of Ceridwen and Taliesin
Note that Gwyon Bach was not a husband or lover of Ceridwen; he was a servant who accidentally tasted a magic potion from the Well of Inspiration (or of Wisdom). The angry goddess swallowed Gwyon Bach, but Ceridwen fell pregnant with Taliesin.
Elffin or Elphin was Taliesin's foster-father.
See the Mabinogion for the full tale of Taliesin.
By Jimmy Joe