Three Golden-Tongued Knights were in Arthur’s Court:
Gwalchmai son of Llew son of Cynfarch, and Drudwas son of Tryffin, and Eliwlod son of Madog son of Uthur: and there was neither king nor lord to whom those came who did not listen to them; and whatever quest they sought, they wished for and obtained it, either willingly or unwillingly.

Drudwas son of Tryffin son of the King of Denmark obtained from his wife three griffins, and they would perform whatever their master demanded of them. A field (of battle) was appointed between Arthur and Drudwas, and nobody was to come to the field but the two of them. Drudwas sent his griffins before him and said "Slay the first who may come to the field." And as Arthur was going, there came the sister of Drudwas who was Arthur's mistress, and out of good will to both of them she hindered Arthur from going to the field; an in the end Drudwas came to the field, supposing hat the griffins had slain Arthur according to his request. And the grinffins snatched him up and slew him, and in the firmament of the sky they recognized him and descended to the earth making the most pitiful wailing, because they had slain their master Drudwas. And there is the song of the griffins over him which was made at that time to commemorate the event, and from it Llywarch Hen obtained the subject to compose this englyn:

Drudwas son of Tryffin, heavy his day
through mischance and oppression
--it was a misfortune to all--
the griffins slew him.

Llywarch the Old sang it.

So we can add Erdudvyl, daughter of Tryffin, to Arthurs lists of conquests,
as she is identified amongst the 'gentle gold torced women of this realm'
in Kullwch and Olwen and must be the lover named above.