Dictionary of National Biography, 1885-1900/Niall (d.405)
NIALL (d. 405), king of Ireland, son of Eochaidh Muighmheadhoin, also king of Ireland, and his second wife Cairinne, is known in Irish writings as Naighiallach, a word translated ‘of the nine hostages,’ but not accounted for by any early record. He made war upon the Leinstermen and the Munstermen, and also fought in Britain and perhaps in Gaul. It has been supposed that he was the Scot whose attack on Stilicho is commemorated by Claudian (In primum Consulatum F. Stilichonis, ii. 247). In tales and poems he is described as having a bard named Laidcenn, and as having been himself educated by Torna Eigeas. He was killed by one of his hostages, Eochaidh, son of Enna Ceannseallach, king of Leinster, at Muir nIcht, perhaps the Ictian Sea, or coast of Gaul. The fact that there is no history of his tomb or burial in Ireland seems to confirm this identification. Though often mentioned in Irish literature, very little is recorded of his time, and that he is one of the best-known kings of Ireland is due to the fame of his descendants. Several of the chief tribes of the north and of Meath regarded him as their ancestor, and it is from him that the O'Neills take their name. The following are the names of those of his fourteen sons who had children, with those of the more important tribes who claimed descent from them: (1) Laeghaire (O'Coindhelbhain); (2) Conall Crimhthainne (O'Melaghlin); (3) Fiacha (MacGeoghegan and O'Molloy); (4) Maine (O'Catharnaigh), all these in Meath, and in the north; (5) Eoghan (O'Neill); (6) Conall Gulban (O'Cannanain and O'Donell). The descendants of Cairbre and Enda Finn are less famous.
In the ‘Book of Leinster,’ a twelfth-century manuscript (fol. 33, col. 2, l. 10), is a poem by Cuan O'Lothchain containing tales of Niall's childhood. In the ‘Book of Ballymote,’ a manuscript of the fifteenth century, the history of his life is related in prose and verse (fol. 265, cols. a and b). In the ‘Leabhar Buidhe Leacain,’ a fourteenth-century manuscript, is a lament for him ascribed to Torna Eigeas, but obviously of much later date. He is always described as having long yellow hair.
[Book of Leinster, facs.; Book of Ballymote, facs.; Annala Rioghachta Eireann, vol. i.]