Dogfael
Dogfael ab Ithael ap Ceredig was a cousin of David, and dedications to him in south-west Wales are in a variety of forms including Dogmael, Dogwell and Degwel. He is referred to as a cousin of David in poetry addressed to David, such as in 'Awdl-gywydd i Ddewi Sant' by Lewys Glyn Cothi.
Further reading
S. Baring-Gould and John Fisher The Lives of the British Saints (London: Honourable Society of Cymmrodorion, 1908), 349–51 View online
Barry J. Lewis Bonedd y Saint: An Edition and Study of the Genealogies of the Welsh Saints (Dublin: Dublin Institute for Advanced Studies, 2023), §2