St Méen, in Latin Mevennus, Also Melanus, Abbot in Brittany

From Fr Alban Butler's Lives of the Saints:

HIS eminent virtues, his wonderful miracles, his monastery, and his tomb famous for the devotion of the pilgrims who visit it, have rendered his name most illustrious among the saints in that country. In the legend of his life he is usually called Conard-Meen. He was born of a rich and noble family, in the province of Gwent in South Wales, and is said to have been related by the mother to Saint Magloire and St. Samson: he was at least a disciple of the latter, whom he accompanied into Brittany in France, and was employed by him in preaching to the people, of which commission he acquitted himself with admirable zeal and success. A certain count named Caduon having bestowed on him lands on each side of the river Meu, in order to found there a monastery, and Guerech I., count of Vannes, having also declared himself the protector of this religious undertaking, to which he became a munificent benefactor, St. Samson appointed St. Meen, about the year 550. This was the origin of the abbey of St. John Baptist of Gael, now called St. Meen’s, in the diocese of St. Malo, about nine leagues from Rennes. Such was the reputation of the sanctity of this holy abbot, and of the regularity of this house, that when Judicael, king of Domnone, renounced the world in the twenty-second year of his age, St. Meen had the honor of giving the monastic habit to his sovereign, probably about the year 616. The saint founded another monastery near the Loire, not far from Angers, which he peopled from that of Gaël, and which he often visited. Great numbers were moved by his example and exhortations to shun the troubled ocean of the world, covered with shipwrecks, by flying out of it, that they might steer a more secure course, and convey the goods they got in their voyage safe into port. St. Meen died at Gaël about the year 617. His tomb is frequented by crowds, and many wonderful cures are there wrought, especially of the itch and scab, and other like cutaneous distempers, to which a mineral well, which bears the name of this saint, and in which the patients bathe, seems greatly to contribute. His relics in the wars of the Normans were conveyed to the great abbey of St. Florent, a quarter of a league from Saumur; though a part remains at St. Meen’s. This abbey of St. Meen was converted into a seminary, and given to the Lazarists, or priests of the mission, in 1640. St. Meen is invoked in the English litany of the seventh century, and in the old missal used in England before the Conquest. The calendars of the chief dioceses of Brittany prescribe his festival to be kept with great solemnity on the 21st of June See Lobineau, Vies des SS. de Bretagne, p. 140.