 This marriage was not considered valid by the church as Cristin was Owain's first cousin, a degree of relationship which according to Canon law prohibited marriage.Giraldus Cambrensis refers to Iorwerth Drwyndwn as the only legitimate son of Owain Gwynedd.Following Iorwerth's death, Llywelyn was, at least in the eyes of the church, the legitimate claimant to the throne of Gwynedd.