Pabo Post Prydein, is most popularly called the son of King Arthuis, though earlier sources suggest that he was this man's brother. His epithet means the Pillar of Britain, said to derive from his keeping Pictish invaders at bay. Though his Kingdom covered the Pennines of central Britain, in later life, Pabo turned to Christianity, abdicated the throne in favour of his sons, Dunaut Bwr and Sawyl Penuchel, and retired to Gwynedd where he founded the church of Llanabo on Ynys Mon (Anglesey). He died there on 9th November 530 and a beautiful medieval stone slab carved with his image can still be seen covering his grave.