Padarn Beisrudd

Padarn Beisrudd ap Tegid literally translates as Paternus of the Scarlet Robe, son of Tegid. His father may have borne the Roman name of Tacitus. Padarn is believed to have been born around AD 400 in the Old North (or Hen Ogledd) of Roman Britain. According to Old Welsh tradition, his grandson, Cunedda certainly came from Manaw Gododdin, the modern Clackmannanshire region of Scotland.
One traditional interpretation identifies Padarn as a Roman (or Romano-British) official of reasonably high rank who had been placed in command of Votadini troops stationed in Clackmannanshire in the 380s or earlier by the Emperor Magnus Maximus. 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.
His command in part of what is now Scotland probably lasted till his death and was then assumed by his son Edern. Edern was the father of Cunedda, founder of the Kingdom of Gwynedd.
The coat of Padarn Redcoat is one of the Thirteen Treasures of the Island of Britain, where it is said to fit perfectly any brave man, but will not fit cowards.
The Life of Saint Padarn contains a story about how King Arthur tried to steal his tunic, which suggests a link or borrowing of a legend connected with Padarn Redcoat.

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.