Rathlin O’Birne Island is a small low-lying, grassy uninhabited island indented all round with channels, bounded by cliffs and even bisected by a sea arch. It lies off the coast line of the cliffs at Sliabh Liag (Slieve League) and marks County Donegal’s most westerly point.
Rathlin O’Birne was where Saint Patrick‘s coppersmith and the first Bishop of Elfin, Saint Asicus, went and lived as a hermit for seven years.
It has a major lighthouse (1846); Irelands first nuclear powered light (thought to have been the world’s most powerful) was switched on here on 15th August 1974. This was replaced with wind power in 1987 when the nuclear battery became worn down. Wind power was replaced with solar energy in 1993, and that is the position to this day.
Two parallel cut stone walls, 2m high and 4m apart, enclose a roadway, once used by the lighthouse keepers as protection against the Atlantic winds on their journey from the beach.
It is not clear how the island came by its name.
The island appears to have been associated with someone or some group named Birn. But were they a local group, did they migrate from “the opposite shore,” or did they move from elsewhere in Ireland? Petty`s 1654 Civil Survey of Donegal Survey listed nine O’Birne families as living in that portion of Donegal, and separately noted “Parrish of Glancollmekill contains island called Raughrey Birne belonging to Thomas Lord ffoliott.”
There are stories in Co. Wicklow that the O’Byrne clan sent troops to the north in the C16th to aide The O’Neill. Did they all return home, or were they granted land in Donegal (as was a group of O’Byrnes in Co. Louth)?
Or could they have been from Co. Tyrone? A 1350 document concerning military service commitments to The O’Donnell said, “32 on Muinter Birn.” This was a reference to an area or a clan in south Co. Tyrone, where there is a town named Minterburn to this day.
Others have suggested a connection with the O’Beirne sept of Co. Roscommon, perhaps based on the legend that Saint Assicus of Elphin established the C5th monastery on the island.
According to The Monastic Settlement on Rathlin O’Birne Island, county Donegal, a 1983 article written by Paul Walsh in the Journal of the Royal Society of Antiquaries of Ireland, nothing is known of the history of this early monastic site, but the Book of Armagh says St. Assicus, who was St. Patrick‘s coppersmith and in charge of a religious community at Elphin in Co. Roscommon, exiled himself for seven years to the island. The Book called the island Rochuil, but Walsh says its identity with Rathlin O’Birne seems certain.