Gildas was born c. 500 in the Clyde valley, but as a child left Scotland and studied under both Saint Illtyd and Saint Cadoc in South Wales. According to one legend, Illtyd dwelt on a narrow and squalid island, but through the prayers of Gildas and other disciples the sea withdrew and the enlarged island blossomed with flowers. Gildas is best-known for De excidio et conquestu Britanniae (On the Ruin and Conquest of Britain), a powerful criticism of the decadent lives of British kings and clergy, whom he blamed for the successes of Anglo-Saxon invaders.

Gildas also preached in the northern parts of Britain, and seems to have been an influential figure in the Irish Church, teaching for a time at Armagh. He later sailed to Brittany, living as a hermit on the Isle of Houat before being persuaded by local fishermen to found a monastery at Rhuys. He died in Brittany c. 570. To Gildas is attributed a Lorica, possibly composed when plague threatened Brittany, which itemises every part of the body in its prayer for protection. It is said that, if repeated frequently, it will add seven years to your life and that you will not die on a day when it is repeated.

From the Appletree Press title: A Little Book of Celtic Saints.