Dictionary of National Biography, 1885-1900/Muircheartach (d.533)
MUIRCHEARTACH (d. 533), king of Ireland, was son of Muireadhach, son of Eoghan, eldest son of Niall Naighiallach, and is usually spoken of in Irish writings as Muircheartach mor macEarca. His mother's name was Eirc, daughter of Loairn (Book of Leinster, 183 b, 30), and after the death of his father she married Fergus, son of Conall Gulban, son of Niall, by whom she was mother of Feidilmid, father of Columba [q. v.], so that Muircheartach was one of the kings to whom the saint was related (Adamnan's Life of St. Columba, ed. Reeves, p. 8). A tract in the ‘Book of Ballymote’ states that in early youth he was banished from Ireland for a murder, and became acquainted in Britain with his kinsman St. Cairnech (Leabhar Breathnach, ed. Todd, pp. 178–93). The succeeding statement that he came from Britain to assume the kingship of Ireland, landing at the mouth of the Boyne, is contrary to the evidence of the chronicles. He is first mentioned in the ‘Annals of Ulster’ in 482 as fighting in the battle of Ocha in Meath, in alliance with the Dal nAraidhe and the Leinstermen against Oilill Molt, king of Ireland, who was slain, and Lughaidh [q. v.], cousin of Muircheartach made king. In 489 he led the Cinel Eoghain, of whom he was chief, against Oengus mac Nadfraich, the first Christian king of Munster, and slew him in the battle of Cellosnadh, now Kellistown, co. Carlow. Illann, son of Dunlaing, one of his allies in this battle, led the Leinstermen against him in 497, and was defeated at Indemor, co. Kildare. The brother of Duach Teangumha, king of Connaught, had put himself under the protection of Muircheartach, but was carried off by the Connaughtmen. The Cinel Eoghain were at once led by their chief into Connaught, and won a victory in 504, killing the king in the Curlieu Hills.
In 517 Lughaidh died, and Muircheartach soon after became king of Ireland. After further war with the Leinstermen, he attacked the Oirghialla, the only important neighbours with whom he had not fought, and conquered from them the northernmost part of their territory, from Glen Con to Ualraigh, both in co. Derry, a region which remained in the possession of the Cinel Eoghain till the plantation of Ulster. The Leinstermen again attacked him in 524, but he defeated them at Athsighe, a ford of the Boyne, and two years later invaded Leinster, winning battles at Eibhlinne, at Magh Ailbhe, at the Hill of Allen, and at Kinneigh, all in the co. Kildare; afterwards ravaging the district known as the Cliachs in Carlow. In the same year he fought the battle of Aidhne against the Connaughtmen. His wife was Duaibhsech, and she bore him five sons, of whom three were dead in 559, when Domhnall and Feargus became for three years joint kings of Ireland. He had a concubine, Taetan, who was of a tribe which he had dispossessed from the neighbourhood of Tara. She revenged the wrong by setting fire to the house of Cleitech, on the Boyne, where he was drunk, on All-halloween in 533. His death is the subject of a very old bardic tale, ‘Oighidh Mhuircheartaigh moir mic Earca.’ His exploits were celebrated in a poem beginning ‘Fillis an ri Mac Earca alleith na Neill,’ by Ceannfaeladh fodhlumhtha, who died in 678. It describes how he carried off hostages from Munster, and gives some idea of the scale of great victories in his time in the expression ‘Foseacht beiris noi ccairpthi’ (‘Seven times did he carry off nine chariots’).
[Annala Rioghachta Eireann, i. 150–76; Annals of Ulster, ed. Hennessy, vol. i.; Book of Leinster, facs. fol. 24 a and 183 b, 18; Book of Ballymote, facs. fol. 48 b; J. O'Donovan's Battle of Magh Rath, p. 145; Leabhar Breathnach, ed. Todd; Book of Fenagh, ed. Hennessy; Lives of Saints, from Book of Lismore, ed. Stokes; Transactions of Iberno-Celtic Society, 1820, ed. O'Reilly.]