John Morris surmised that the line of a certain Morcant Bulc referred to these monarchs, chiefly because he identified this man as the murderer of Urien Rheged who was, at the time, besieging Lindisfarne.
John Morris supuxo que a liña dun tal Morcant Bulc se refería estes monarcas, principalmente porque identificaba a este home como o asasino de Urien Rheged que estaba nese momento cercando Lindisfarne.