Sawyl Penuchel
Son of Iaen and brother of Sulyen, Bradwen, Moren, Teregud, and Caradawg. He came from Caer Dathal and was one of Arthur’s warriors.
In the Welsh Bonedd y Arwyr he is, together with his brother Cradawc (Caradawg), said to be related to Arthur through his sister’s marriage to Arthur. They are called gwyr Kaer Tathal (‘men of Caer Dathal’).
The medieval Welsh tale Culhwch and Olwen, Siawn is Arthur’s cousin, being the son of Gwriad, who is Uther’s brother. This makes Siawn a cousin of Arthur on his mother’s side, as Arthur’s mother, Igraine, was married to Uther.
Note
Bonedd y Arwyr is Welsh, meaning “The Lineage of the Heroes” or “The Descent of the Heroes.”
Source
Culhwch and Olwen | Late 11th century
Bonedd yr Arwyr |