NIGHTBRINGER | The Arthurian Encyclopedia

Iaen


In Welsh tradition, his sons, TeregudSulyenBradwenMorenSiawn, and Caradawg, were at Arthur’s court and his daughter Eleirch had a son by Arthur.

They were said to come from Caer Dathal, and were related to Arthur through Uther.


Source
Culhwch and Olwen | Late 11th century