Question: Who is Catrin Ferch Owain Glyndŵr's paternal grandfather?
Sentence (from "Owain Glyndŵr"): Glyndŵr was a descendant of the Princes of Powys through his father Gruffudd Fychan II, hereditary "Tywysog" of Powys Fadog and Lord of Glyndyfrdwy, and of those of Deheubarth through his mother Elen
Relevant evidence: Yes