A biography of Niall can be constructed from sources such as the "Roll of Kings" section of the 11th-century
Lebor Gabála Érenn, the
Annals of the Four Masters, compiled in the 17th century, chronicles such as
Geoffrey Keating's
Foras Feasa ar Éirinn (1634), and legendary tales like the 11th-century "The Adventure of the Sons of Eochaid Mugmedon" and "The Death of Niall of the Nine Hostages".
Accession Seeing Niall's popularity among the nobles, Mongfind demands that Eochaid name a successor, hoping it will be one of her sons. Eochaid gives the task to a
druid, Sithchenn, who devises a contest between the brothers, shutting them in a burning forge, telling them to save what they can, and judging them based on which objects they choose to save. Niall, who emerges carrying an anvil, is deemed greater than Brión, with a sledgehammer, Fiachrae with bellows and a pail of beer, Ailill with a chest of weapons, and Fergus with a bundle of wood. Mongfind refuses to accept the decision. Énna's son
Eochaid is named as Niall's killer in all sources, although the circumstances vary. All sources agree he died outside Ireland. The earliest version of the
Lebor Gabála says Eochaid killed him on the
English Channel, later versions add that Niall was invading
Brittany when this happened. Keating, quoting a Latin Life of Saint Patrick, says that Niall led Irish raids on Roman Britain, and in one of those raids Patrick and his sisters were abducted. Keating associates these raids with those mentioned by
Gildas and
Bede, and deduces that, since some Irish sources say Patrick was abducted from Brittany, that Niall's raids must have extended to continental Europe as well. a poem attributed to the same poet in
Lebor na hUidre credits him with going to the Alps seven times. The Scottish
Clan Ewen of Otter, Gilchrist;
Clan Lamont; the MacSorleys of Monydrain, (of
Clan MacDonald of Dunnyveg a branch of
Clan Donald);
Clan Maclachlan;
Clan MacNeil, and the
MacSweens all claim descent from an Irish prince of the
O'Neill dynasty, Ánrothán Ua Néill/Anrothan O'Neill, son of Áed, son of
Flaithbertach Ua Néill,
King of Ailech and
Cenél nEógain, who left Ireland for
Kintyre in the 11th century and died 1036.
Y Chromosome Analysis Following a 2006 hypothesis by Moore et al. suggesting that his Y chromosomal signature had been discovered, popular science journalists and
genetic testing companies began promoting the theory that millions alive today have an unbroken descent from Niall.
Geneticists at
Trinity College Dublin found that 21 per cent of men from north-western Ireland, 8 per cent from all of Ireland, a substantial percentage of men from western and central Scotland, and about 2 per cent of men from New York bore the same
Y-chromosome haplotype. The geneticists estimated that about 2–3 million men bear this haplotype. Moore et al. concluded that these men descend from "a single
early-medieval progenitor" and implied this was associated with Niall's dynasty. While Moore et al. did not specifically state that Niall was the progenitor of M222, journalists quickly jumped to that conclusion. According to the PBS documentary series
Finding Your Roots,
Bill O'Reilly,
Stephen Colbert,
Colin Quinn,
Bill Maher, and the show's host,
Henry Louis Gates Jr. all display STR markers consistent with the Irish Modal Haplotype. The series suggested that Niall may have been the most
fecund male in Irish history. Indeed, more recent estimates indicate that the R1b-M222 subclade marked by the Moore et al. haplotype probably originated in the 2nd millennium BC, long before Niall is claimed to have lived, so his descendants would only represent a minority of men in this group even if Niall had been a historical figure. Perhaps even more problematic is the dearth of M222 lineages in Midlands samples. We would expect to find a large concentration of Niall's descendants there, as the Southern Uí Néill were dominant in that region, but we do not. Because of that, the identification of M222 with Niall's descendants is "difficult to justify".
Origin of his epithet There are various versions of how Niall gained his epithet
Noígíallach. The saga "The Death of Niall of the Nine Hostages" says that he received five hostages from the five provinces of Ireland (
Ulster,
Connacht,
Leinster,
Munster and
Meath), and one each from
Scotland, the
Saxons, the
Britons and the
Franks. Keating says that he received five from the five provinces of Ireland, and four from Scotland. O'Rahilly suggests that the nine hostages were from the kingdom of the
Airgialla (literally "hostage-givers"), a satellite state founded by the Ui Néill's conquests in Ulster, noting that the
early Irish legal text Lebor na gCeart ("
The Book of Rights") says that the only duty of the
Airgíalla to the King of Ireland was to give him nine hostages. ==Family tree==