Cynfyn ap Gwerstan

Cynfyn ap Gwerystan (born c. 990) — sometimes spelled Kynvyn, Kynwyn, Cynvyn, or Kynfyn — was a Welsh nobleman, principally known on account of his son Bleddyn ap Cynfyn, who established the House of Mathrafal over Powys as a consequence of a Saxon invasion in 1063.

His father was Gwerystan ap Gwaithfoed and his mother Nest ferch Cadell. Cynfyn married Angharad ferch Maredudd, daughter of Maredudd ab Owain, king of Dyfed.

Wolcott states that "When he was born c. 985, there was no expectation Cynfyn would ever become a king. His ancestors had been among the leading men of Powys for hundreds of years, but the kingdom had been ruled by another ancient family which was still in power. His father had married the daughter, and only child, of King Cadell ap Brochwel II. But Cadell had brothers and nephews eligible to rule after his death; seldom did a Welsh kingship descend through female lines, and never if there was an eligible qualified male heir. But such a circumstance appears to have occurred in 1023, when the existing king died (or was killed) fairly early in his life and at a time when both his son and other qualified males in the Royal Family were too young for kingship." However, an ancestor of Cynfyn was Cynwrig, son of Tegonwy, a descendant of Casnar Wledig whom in some cases is made son of Caderyn, while in more ancient documents he is son of Gloyw Gwlat Lydan and Great Grandson of Ludd ap Beli Mawr, making him a descendant of a direct patrilineal line from the house of Gwertherion or the Celtic Kings of Britain, which could explain why Gwerstan was chosen to marry Nest ferch Cadell.

Wolcott further argues that Cynfyn was a caretaker monarch until 1033, when Iago ap Idwal of Gwynedd came of age and took the kingship. A dictionary of biography of eminent welshmen

With an unnamed Irish princess, daughter of Sitric Silkbeard c. 960 he had the following issue:

After the death of his first wife, possibly in childbirth, he married Angharad (daughter of Maredudd ab Owain), widow of Llywelyn ap Seisyll and had the following issue:

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