S. Laserian was the son of Cairel, a nobleman of Ulster, and of Gemma, daughter of Aidan, king of the British Scots. The year of his birth is not known, and the early part of his life is involved in obscurity. According to one account he was a disciple of Fintan Munnu, while another places him under an abbot Murin, probably Murgen of Glen-Ussen. When arrived at a mature age, he is said to have proceeded to Rome, and to have remained there for fourteen years. Then, we are told that he was ordained priest by S. Gregory the Great, and soon after returned to Ireland. Coming to Old Leighlin, he was affectionately received by S. Cobban, who governed the monastery there. This saint conceived such a high opinion of S. Laserian that he gave up to him his establishment and went to erect a monastery elsewhere. Laserian is said to have had 1,500 monks under him at Leighlin. At this time there was controversy in Ireland as to the right time for celebrating Easter. Some were for adopting the new Roman method, but the bulk of the clergy and nation were attached to the old computation, until the year 630, when, in consequence of an admonitory letter from pope Honorius I., a synod was held at or near Leighlin, which was attended by a great number of persons, and amongst others by the heads of several of the greatest religious establishments in the South of Ireland. S. Laserian spoke in favour of the Roman system, and was strenuously opposed by S. Fintan Munnu of Taghmon. The heads of the old establishments declared that they had been directed by their predecessors to follow the practice of the successors of the apostles, and accordingly proposed that Easter should for the future be celebrated at the same time with the Universal Church. This was agreed to, but the contest again breaking out, it was resolved by the elders that some wise and humble persons should be sent to Rome, as children to their mother. Among these was S. Laserian, in all probability, for he certainly was at Rome the same year, after the council of Maghlene. These deputies saw at Rome how people from various countries celebrated Easter at one and the same time, and they returned to Ireland to announce to those who had deputed them, that the Roman method of keeping Easter was that of the whole Christian world. Thenceforth, about the year 633, the new Roman cycle and rules were received in the Southern division of Ireland. Before his return to his native island, Laserian had been consecrated bishop by pope Honorius I. He survived his return only a few years, as he died on April 18th, 639. He was buried in his own church at Leighlin, and his memory is greatly revered in the province of Leinster.
In one of the footnotes on this page, Baring-Gould has a go at a popular French hagiographical work, complaining of ‘the manner in which they suppress facts, and place what they know to be apocryphal before the unsuspicious reader as historical fact… these acts are full of such absurdities as this, they make the woods of Italy swarm with lions and panthers.’ I must see if I can find out why he was so desperate to make the lives of saints sound ordinary or ‘believable’ and to expunge anything apparently odd or inconsistent. Dear me! Fortunately we are able to think for ourselves. What we need is not heavy-handed editing but interpretation and commentary, clear notes about sources, etc. I dare say there were lions and panthers in the Italian forests once upon a time, as there were bears and wolves in Britain – but they may have other purposes in a story other than the strictly literal, and it is not a good idea to simply get rid of them! Anyway, in this life of St Laserian he completely ignores the saint’s strong connections with Scotland. They are not entirely clear – the Holy Island where he spent his youth under the instruction of St Murin may have been Iona, and he may have been a hermit on an islet off Arran (see Barrett) which also became known as Holy Island. And of course on the east coast Lindisfarne is called Holy Island… but better to gather all these details together and see what can be made of them, rather than to pick and choose.