Niall of the Nine Hostages — All our writers agree that this monarch infested Britain and the coasts of Gaul, following in the track of his predecessor, Criomthann Mor mac Fiadaigh, who planted a colony of Mustermen in Wales. The devastations of Niall in Britain are thus referred to in a very ancient life of St. Patrick, formerly in the possession of Archbishop Ussher, who gave the following quotation from it in his Primordia, p. 587: ‘Scoti de Hibernia sub rege suo Neill Naeigiallach multum diversas provincias Britanniae contra Romanum Imperium, regnante Constantio filio Constantini, devastabat: contendere incipientes Aquilonalem plagam Britanniae. Et post tempus, bellis et classibus Hiberniensis expulerunt habitores terrae illius; et habitaverunt ipsi ibi.’
The devastations of Niall in Britain and Gaul are thus alluded to by Mr. Moore, who justly considers this within the authentic period of Irish history: — ‘The tottering state of the Roman dominion in Gaul, as well as in every other quarter, at this period, encouraged the Hero of the Nine Hostages to extend his enterprises to the coast of Brittany, where, after ravaging all the maritime districts of the north-west of Gaul, he was at length assassinated, with a poisoned arrow, by one of his own followers, near the Portus Iccius, not far, it is supposed, from the site of the present Boulogne. It was in the course o this predatory expedition that, in one of their descents on the coast of Armoric Gaul the soldiers of Niall carried off with them, among other capties, a youth then in his sixteenth year, whom Providence had destined to be the author of a great religious revolution in their country; and whom the strangely fated land to which he was then borne, a stranger and a slave, has now, for fourteen hundred years, commemorated as its great Christian apostle. History of Ireland, vol. i. p. 152.’