Pabo Post Prydain (supp. fl. before 500) was a king from the Hen Ogledd or Old North of sub-Roman Britain.[1] According to tradition Pabo "the Pillar of Britain" was driven out of the North in 460 and settled in Anglesey.[2] He is said to have been buried in the area.[1] From the 14th century at least, when a stone cross was erected in the ruler's memory in the abbey's churchyard, Pabo has been identified as its founder, having retired, as many Welsh kings are said to have done, to a heremitic retreat.