The following is taken from Fr. Thomas Walsh's History of the Irish Hierarchy at p. 451:
Clonfert in the barony of Longford and near the river Shannon and a bishop's see. Saint Brendan of Clonfert had been according to some authorities a native of Connaught but the more ancient and consistent accounts assure us that he was born in Kerry. His father was Finloga of the distinguished family of Hua Alta. Brendan was born in the year 484 and is said to have received his education under a bishop Ercus. We are also assured that he studied theology under Saint Jarlath of Tuam who was then old and infirm or rather conferred with the bishop of Tuam on those religious subjects he is also said to have attended lectures in the great school of Clonard under Finnian who was then probably as old as Brendan himself.
To atone for the death of a person who had been drowned and to which melancholy event Brendan feared he had involuntarily contributed he is said to have gone to Brittany through the advice of Saint Ita who it seems was a relative of his. It is said that when he was a year old the bishop Ercus placed him under the care of this celebrated virgin and that he was reared by her during the space of five years. Having paid a visit to Gildas who was then living in that country and advanced in years and who retired to Brittany also between the years 520 and 530, he went to another part of Brittany where he formed a monastery or school at Ailech, the ancient Alectum, and at present St. Malo. It is also added that he erected a church in a place called Heth, somewhere in the same province.
According to some accounts the famous voyages of this saint took place after his arrival in Brittany but according to the Irish authorities they were undertaken from a port in Kerry, Brendan's hill, and had been terminated before his departure from Ireland to that country. With regard to those voyages it can be admitted that Saint Brendan sailed in company with some other persons towards the west in search of some island or country the existence of which had been known. St. Barriutlms and Mernoc, a disciple of his, are said to have been in that country and it is added that the account given of it by Saint Barrinthus induced Brendan to undertake his voyage. In that account it is represented as a western country or island but yet so large that although they traversed it for fifteen days they could not reach the end of it. The direction of Brendan's voyage is said to have been "contra solstitium aestivale" by which is probably meant the north west point, alluding to the setting of the sun in summer. After fifteen days sailing the wind ceased and the navigators though there was wind now and then left the vessel to itself without knowing its course. It could have thus arrived in America and an idea one would suppose existed that there had been a western country far distant from Ireland. Another native of Munster who will be noticed in his proper place set out from his home resolved to undertake a similar voyage in quest of an unknown island. It is said that Saint Brendan laid in provisions for fifty days which proves that his voyage was considered a long one. His voyages are said to have continued for seven years.
Soon after his return from Britanny he founded the monastery of Clonfert. For this monastery and others connected with it, Brendan drew up a particular rule which was observed for many centuries by his successors having been particularly esteemed as an angel is said to have been the dictator of it to Brendan. He presided over three thousand monks partly at Clonfert and in other houses of his institution in different parts of Ireland, all of whom maintained themselves, like St. Paul, by the labor of their own hands.
He established a nunnery at Enachdune over which his sister Briga presided as abbess. Another cell was erected by him in Innisquin an island of Lough Corrib. At a late period of his life he paid a visit to St. Columbkille in one of the western isles of Scotland. St. Brendan died at Enaghdune in his sisters' nunnery on the 16th of May, A.D. 577, and in the 94th year of his age.
From that place his remains were conveyed to Clonfert and there interred. This great saint is usually styled abbot. St. Patrick, when in the south of Ireland, foretold that the great Brendan would be born in West Munster Kerry The church of Ardfert was dedicated under his name.
