Saint Gunthiern, Abbot in Brittany

From Fr Alban Butler's Lives of the Saints:

THIS saint flourished in the sixth century. He was a prince in Wales, which he left in his youth, and retired into Armorica to live a recluse. He stopt at the isle of Groie, which is about a league from the mouth of the Blavet. Grallon was then lord of the isle, and was so edified at his conversation, that he bestowed on him, for founding a monastery, the land between the confluence of the river Isol and Ellé. For which reason even to this day, the abbey is called Kemperle, which in the old British language signifies the conflux of Ellé. One year that a prodigious swarm of insects devoured the corn, Guereck I., count of Vannes, dreading a famine, deputed three persons of quality to engage the saint’s prayers to God for turning away the scourge. Gunthiern sent him water which he had blessed, which he desired to be sprinkled over the fields, and the insects were destroyed. The count, in gratitude for this extraordinary blessing, gave him the land near the river Blavet, which was then called Vernac; but is now known by the name of Hervegnac or Chervegnac. The saint, it is thought, died at Kemperle. During the incursions of the Normans, his body was concealed in the isle of Groie. It was discovered in the eleventh century, and brought to the monastery of Kemperle,* which now belongs to the Benedictine Order. St. Gunthiern is patron of this abbey as well as of many other churches and chapels in Brittany. He is mentioned in ancient calendars on the 29th of June, but the moderns place his feast on the 3d of July. See Lobineau, Vies des SS. de Bretagne, p. 49.