Constantine, the son of Kenneth, and the first inheritor of the name of his Pictish ancestor, ascended the throne of Scotland at an era when the efforts of Gorm, Eric, and Harald Harfager to consolidate the petty states of Scandinavia into the respective kingdoms of Denmark, Sweden, and Norway, had given a fresh stimulus to the incursions of the Vikings upon the British Isles, by dispossessing and driving from their homes many of the minor chieftains who refused to submit to their authority. Ireland as well as Britain had suffered from the attacks of these marauders as early as the close of the eighth century, but it was not before the middle of the following century that the Northmen first established themselves permanently in the former country, principally in Dublin and its neighbourhood, where the recollection of one branch of the invaders is still retained in the name of the adjacent district of Fingall.[42] [Sidenote: A. D. 850] About ten years after the first settlement of the Norsemen a fresh fleet arrived off the Irish coasts, under the command of leaders claiming to belong to “the royal race of Lochlan,” to whom the native annalists have given the name of Du Gall, or Black Strangers, in contradistinction to their predecessors the Fin Gall or White Strangers, epithets which were derived probably from some long forgotten distinction in dress or armour rather than from any difference in personal appearance or in nationality.[43] Driven from Dublin and from their settlements upon the coast of Uladh, the Fingall collected in great numbers from every quarter, and soon returned with their whole force to re-assert their lost ascendancy; but a combat between the two fleets, which is said to have lasted during three days and nights, confirmed the superiority of their rivals, and in the following year Olave the Fair, the son of Ingiald, an Upland chieftain of the same race as Harald Harfager, landed with his followers [Sidenote: A. D. 854.] amongst his countrymen, and at once assumed the lead over all the Northmen of Ireland. In alliance with the Norwegian Olave was the Danish Ivar or Ingvar, the most renowned warrior amongst all the northern chieftains, whom tradition has made a son of Ragnar Lodbroc, and the ruthless avenger of his slaughter.[44]