Padarn is believed to have been born in the early 4th century in the Old North (or Hen Gogledd) of Roman Britain.
According to Old Welsh tradition, his grandson, King Cunedda, came from Manaw Gododdin, the modern Clackmannanshire region of Scotland.
Alternatively, he may have been a frontier chieftain in the same region who was granted Roman military rank, a practice attested elsewhere along the empire's borders at the time.
In M J Trow's fictional Britannia series, Padarn Beisrudd is one of the central characters.
He is given the Latinised name of Paternus and portrayed as a limitanei soldier guarding Hadrian's Wall.