Erbin ap Custennin

See Peter Bartrum, https://www.geni.com/documents/view?doc_id=6000000173393640874 (February 8, 2023; Anne Brannen, curator)

From Darrell Wolcott, Center for the Study of Ancient Wales: " As to Gereint ap Erbin, there were two men of that name, one historic and the other a character in the Mabinogion tale "Gereint and Enid". The latter may have been "real" also but the tale about him is fiction. He is described as the son of Erbin ap Custinnen Gornew (Cernyw) and a first-cousin of King Arthur (based on the false claim that the father of Arthur was a son of Custennin). If historic, nothing really known about him, but he would have been born c. 480 to a c. 450 Erbin ap Custinnen Gorneu.

         The Gereint ap Erbin who had 4 named sons (Selyf, Cyngar, Iestyn and Cadwy/Cado) is called "admiral" in many accounts.  (llyngesydd).   He was born c. 450, the son of Erbin ap Cynfawr, which Erbin was a brother of Custinnen Gorneu.

         JC 20, 10 is the only citation which gives the correct ancestry of this Gereint, which Bartrum then chooses to corrupt by inserting "Custinnen" to make it agree with several other citations which had wrongly inserted Custinnen into his pedigree. (likely based on the the Mabinogion tale of a different Gereint ap Erbin)" (Steven Ferry, February 29, 2020.)