The entry in the Martyrology of Donegal at January 27 must rank as one of the strangest notices ever recorded of a holy woman:
27. F. SEXTO KAL. FEBRUARII. 27MUIRGHEIN : i.e., a woman who was in the sea, whom the Books call Liban, daughter of Eochaidh, son of Muireadh ; she was about three hundred years under the sea, till the time of the saints, when Beoan the saint took her in a net, so that she was baptized, after having told her history and her adventures.
The earlier calendar of Saint Oengus also records Muirgen on 27th January:
F. vi. kl. My God loved Muirgen,A miraculous triumphant being ;They achieved bright victories in presence of kingsAgna and Conx, virgins.
and the holy virgin, Murgeilt, is commemorated at the vi. of the February Kalends, i.e. the 27th of January, in the Scottish Kalendar of Drummond.
She also features in the Annals of the Four Masters:
The Age of Christ, 558.In this year was taken the Mermaid, i.e. Liban, the daughter of Eochaidhn, son of Murieadh, on the strand of Ollarba, in the net of Beoan, son of Inli, the fisherman of Comghall of Beannchair.
A footnote adds 'Her capture as a mermaid is set down in the Annals of Ulster under the year 571: “Hic anno capta est in Muirgheilt”
J. O'Donovan, ed. and trans., Annals of the Kingdom of Ireland by the Four Masters, vol.1 (Dublin, 1856), 201.
The legend of Muirgen is found in the Lebor na h-Uidri or Book of the Dun Cow. It tells the story of how the woman Liban was transformed into the saint Muirgen and establishes the setting as the north-eastern part of Ireland around what is now Larne, County Antrim:
This Liban was the daughter of Eochaidh, from whom Loch Eathach, or Lough Neagh, was named, and who was drowned in its eruption [A. D. 90], together with all his children, except his daughter Liban, and his sons Conaing and Curnan. Liban, was preserved from the waters of Lough n-Eachach for a full year, in her grianan, [palace] under the lake. After this, at her own desire, she was changed into a salmon, and continued to traverse the seas till the time of St. Comhgall of Bangor. It happened that St. Comhgall dispatched Beoan, son of Innli, of Teach-Dabeoc, to Rome, on a message to Pope Gregory [Pope, A. D. 599-604], to receive order and rule. When the crew of Beoan's currach were at sea, they heard the celebration of angels beneath the boat. Liban, thereupon, addressed them, and stated that she had been 300 years under the sea, adding that she would proceed westward and meet Beoan, that day twelvemonths, at Inbher-Ollarbha [Larne], whither the saints of Dalaradia, with Comhgall, were to resort. Beoan, on his return, related what had occurred, and, at the stated time, the nets were set, and Liban was caught in the net of Fergus of Miliuc; upon which she was brought to land, and crowds came to witness the sight, among whom was the Chief of Ui Conaing. The right to her being disputed by Comhgall, in whose territory,-and Fergus, in whose net,-and Beoan, in promise to whom,-she was taken, they prayed for a heavenly decision; and the next day two wild oxen came down from Carn-Airend; and on their being yoked to the chariot, on which she was placed, they bore her to Teach-Dabeoc, where she was baptized by Comhgall, with the name Muirgen i.e. Born of the sea, or Muirgeilt i.e. traverser of the sea. Another name for her was Fuinchi.
Commenting on the presence of this 'wild legend' in the Annals, Irish Anglican Bishop, William Reeves, sought for a rational explanation:
A seal, or or some such tenant of the sea, may have been caught in the nets of Comgall's fisherman, and, as a "sancta Liban [Liban 'maris mulier']" flourished about the year 580 "sub magisterio S. Comgalli", the following generation may have converted the seal into a liban, and St. Liban into a muirgelt (mermaid).
Reeves also adds the interesting detail that belief in mermaids persisted in the County Antrim area in his own time:
Nay, it is not twenty years since, in this age of light, a large company travelled all the way from Belfast to this neighbourhood, to see a mermaid which was reported to have been taken in Island Magee!
This is presumably the same incident referred to here:
In the same area [where Liban was captured] the Belfast Commercial reported the stranding of a mermaid in 1814 at Portmuck in Islandmagee, where hundreds of people flocked to see her. In his excellent book, The Fishermen of Dunseverick, James McQuilken recounts the sighting of a mermaid by the crew of one of Dunseverick’s fishing boats, while returning from their fishing grounds off Rathlin. One spring morning in the 1880s she was spotted on the rocks at Keardy’s Port. On landing the crew walked quickly to the rock, but she had disappeared. The cynical, of course, may blame the local seal population as the source of these apparitions.
Canon O'Hanlon, while saying with a considerable degree of understatement that 'we must receive only with great diffidence the various bardic accounts regarding Muirgen', nevertheless, supplies a fitting ending to the story:
'The romantic tale of her adventures concludes with a statement, that after her capture, the clerics gave her a choice to be baptized and go to heaven within an hour, or to wait three hundred years on earth, on condition of her afterwards attaining happiness. She chose to die that very hour. She seems to have been buried at Teach Dabeoc, on Lough Derg, in the county of Donegal. Miracles and wonders were there wrought through her. There, too, as God ordained for her in heaven, like every holy virgin, she was held in honour and reverence'.
So, thus ends the curious tale of Muirgen, the mermaid who became a saint. Perhaps stories like this demonstrate a wish to literally baptize elements of Ireland's pagan culture. It certainly is not the only example. O'Hanlon draws a parallel between Liban swimming the seas for 300 years until Saint Comghall arrives on the scene and the legend of Fionnuala, the daughter of Lir, who spent centuries in the form of a swan until the coming of Christianity set her free. Yet perhaps there was also a real holy woman called Muirgeilt, as the Drummond Kalendar says, whose story somehow became entwined with this legendary daughter of Lough Neagh.