 He appears in the Middle Welsh genealogical text "Bonedd Gwŷr y Gogledd" as the son of the equally obscure Gwrwst Lledlwm, a grandson of Coel Hen, and grandfather of renowned Urien Rheged.He is assumed, like Urien, to have ruled Rheged, including Catterick.His two sons appear at the head of two later dynasties.