Gwriad ap Dwywg
Was a Welsh prince who seems to have re-established himself on the Isel of Man around the year 800 or later. As Man was prdominately Irish at the time, the presence of a Welsh chieftain suggests an interloper rather than a native ruler. Although Man probably remained in Welsh hands for several generations, it subsequently fell under Viking control.
Dwywg ap Llywarch
Said to have ruled the Isle of Man.
Llywarch Hen ap Elidir
An early king of the Isle of Man, he didn't have the temperament to be a king, so he retired to become a poet at the court of the kings of Powys and Gwynedd.