[3] Samson later sought a greater austerity than his school provided, and so moved to Llantwit's daughter house, the island monastery of Caldey off the coast of Dyfed (Pembrokeshire), Wales, where he became abbot after the death of Pyr.

However, in the 20th century, genealogical studies threw further light on the subject, and the pillar is now considered by many to be "one of the oldest inscribed Christian monuments in Britain".

[6] Legend has it that Saint Samson of Dol was threshing corn in Penparcau, Ceredigion on the hillside of Pen Dinas (a Celtic Hillfort) when the larger part of his flail broke and landed across the valley in the Abbey at Llanbadarn Fawr, in anger he threw the smaller part over the valley too and these were used to make the three celtic crosses which now stand in the church.

The Anglo-Saxon King Athelstan (r. 924–939) obtained several relics of Samson, including an arm and a crozier, which he deposited at his monastery at Milton Abbas in Dorset.

He is mentioned as follows: "At Dol in Brittany (died) Samson, abbot and bishop, who having learned the Gospel and monastic discipline in Wales from Illtud, spread these in Domnonée.