Owen Gwynned is, along with H. P. Lovecraft, a descendant of Llunwy of Wales.
Behind the Mythos[]
He most likely is a reference to Owain Gwynedd, a medieval Welsh King.
Lovecraft jokingly introduced him in his 1933 family tree: (HPL: Selected Letters of H. P. Lovecraft 4.617)
Azathoth / ___________________________/__________________________________ / / / Nyarlathotep The Nameless Mist Darkness (The ancient patrician / / gens Viburnia of Haec / / RESPVLICA.ROMANA) Yog-Sothoth------------+---------Shub-Niggurath / / / ____________/___________________ L. Viburnius Marco / / / Nug Yeb / / / P. Viburnius Marco / / Legatus of Legio 11., Cthulhu* Tsathoggua* station'd at Isca Silurum, / / in Britannia Secunda / / in A. D. 103 Shaurash-ho Yabou / / / / / / / Yogash the Ghoul Nush the Eternal / / / / / / / K'baa the Serpent Gilles Grenier, / / Lord of Averoigne / ** / / Viburnia-----------+-----------Ghoth the Burrower / / (one of the Little People) Hippolyte Le Sorcier, / ancestor of Llunwy of Wales Clark Ashton Smith ancestor of Owen Gwynedd and of |H.P.L. * First of their respective lines to inhabit this planet. ** This union was an hellish and nameless tragedy.