St Laserian, Called Molaisre, Bishop of Leighlin, in Ireland

From Fr Alban Butler's Lives of the Saints:

LASERIAN was son of Cairel and Blitha, persons of great distinction, who intrusted his education, from his infancy, to the Abbot St. Murin. He afterwards travelled to Rome in the days of Pope Gregory the Great, by whom he is said to have been ordained priest. Soon after his return to Ireland, he visited Leighlin, a place situated a mile and a half westward of the river Barrow, where St. Goban was then abbot, who, resigning to him his abbacy, built a little cell for himself and a small number of monks. A great synod being soon after assembled there, in the White Fields, St. Laserian strenuously maintained the Catholic time of celebrating Easter against St. Munnu. This council was held in March 630. But St. Laserian not being able to satisfy in it all his opponents, took another journey to Rome, where Pope Honorius ordained him bishop, without allotting him any particular see, and made him his legate in Ireland. Nor was his commission fruitless: for, after his return, the time of observing Easter was reformed in the south parts of Ireland. St. Laserian died on the 18th of April, 638, and was buried in his own church which he had founded. In a synod held at Dublin, in 1330, the feasts of St. Patrick, St. Laserian, St. Bridget, St. Canic, and St. Edan, are enumerated among the double festivals through the province of Dublin. St. Laserian was the first bishop of Old Leighlin, now a village.—New Leighlin stands on the eastern bank of the river Barrow. See Ware, p. 54, and Colgan’s MSS. on the 18th of April.