The titles Baron of Glyndyfrdwy and Lord of Cynllaith Owain were used by the dispossessed former ruling family of Powys Fadog before Owain was proclaimed Prince of Wales in 1400.
Before Owain was recognized as the Prince of Wales in 1400, the titles Baron of Glyndyfrdwy and Lord of Cynllaith Owain were used by the former ruling family of Powys Fadog who had been displaced.