To Ireland itself the results of the wiking invasions were far more disastrous than either to Britain or to Gaul. Owing to the peculiar physical character of their country, to their geographical remoteness from the rest of Europe, and to the political and social isolation which was a consequence of these, the Irish people had never advanced beyond the primitive tribal mode of life which had once been common to the whole Aryan race, but which every European branch of that race, except the Irish, had long since outgrown. In the time of Ecgberht and of Charles the Great Ireland was still, as at the very dawn of history, peopled by a number of separate tribes or septs whose sole bond of internal cohesion was formed by community of blood;—whose social and political institutions had remained purely patriarchal in character, unaffected by local and external influences such as had helped to mould the life of England or of Gaul:—who had never yet coalesced into any definite territorial organization, far less risen into national unity under a national sovereign. The provincial kings of Ulster, Connaught, Leinster and Munster were merely the foremost chieftains among the various groups of tribes over whom they exercised an ever-shifting sway; while the supremacy of the Ard-Righ or chief monarch, to whom in theory was assigned the overlordship of the whole island, was practically little more than a sort of honorary pre-eminence attached to certain chosen descendants of an early hero-king, Niall “of the Nine Hostages”; it carried with it little effective authority, and no territorial power; for the monarch’s traditional seat at Tara had long been a heap of ruins, and a tribal under-king had ousted him from the plain of Meath which in legal theory formed his royal domain.[372] Neither in the monarch himself nor in the provincial chieftains of a state thus constituted could there be found, when the storm-cloud from the north burst upon Ireland, a centre of unity even such as the peoples of Gaul found in their Karolingian sovereigns, far less such as the West-Franks found in the dukes of the French, or such as the English found in their kings of the house of Ecgberht. The stress of the northmen’s attack, which elsewhere gave a fresh impulse to the upgrowth of national life, crushed out all hope of its developement in Ireland. The learning and the civilization of ages perished when Columba’s Bangor, Bridget’s Kildare, Ciaran’s Clonmacnoise, Patrick’s own Armagh, shared the fate of Bæda’s Jarrow and Hild’s Streoneshealh, of Cuthbert’s Melrose and Aidan’s Lindisfarne; and in Ireland there was no Wessex and no Ælfred.

On the other hand, the concentration of the wiking forces upon Britain had given to the Irish an advantage which enabled them to check the spread of wiking settlements in their country; and the failure of all attempts to establish a Scandinavian dominion in Britain destroyed all chance of a Scandinavian conquest of Ireland. The Ostmen never even gained such a footing in Ireland as the followers of Hrolf gained in Frankland: their presence never received the sanction of any Ard-Righ; they were not a compact body occupying the whole of an extensive and well-defined territory, but a number of separate groups settled here and there along the coast, and holding their ground only by sheer hard fighting against a ring of implacable foes. The long struggle may be said to have ended in a defeat of both parties. The Irish kings of Munster succeeded in establishing a more or less effective overlordship over the Scandinavian communities of Limerick and Waterford; and in 989 Malachi II., supreme monarch of Ireland, reaped his reward for nine years of desperate fighting in the submission of the Ostmen of Dublin. The city was blockaded and starved into surrender, and a yearly tribute was promised to Malachi and his successors.[373] Six years later “the ring of Tomar and the sword of Carl”—two heathen relics probably of ancient heroes, which seem to have been treasured as sacred emblems of sovereignty by the Ostmen[374]—were carried off by Malachi as trophies of another victory;[375] and in 999 or 1000 a renewal of the strife ended in a rout of the Ostmen and a great slaughter of their leaders, and Dublin was sacked and burnt by the victorious Irish.[376]

Malachi’s triumph, however, was gained at the cost of a disruption of the monarchy. Malachi himself was displaced by a king of the rival house of Munster, his colleague in the sack of Dublin, the famous Brian Boroimhe;[377] Brian’s career of conquest ended in 1014 on the field of Clontarf, where he was slain in battle with the men of Leinster and the Ostmen;[378] and when Malachi, who now resumed his place, died in 1022,[379] the downfall of the Irish monarchy was complete.[380] The tradition which had so long linked it to the house of Niall had been shattered by Brian’s successes; and Brian had not lived to consolidate in his own house the forces which had begun to gather around himself. Thenceforth the Scandinavian colonies simply furnished an additional element to the strife of the Irish chieftains, and to the rivalry between the O’Briens of Munster and the O’Neills of Ulster for the possession of a shadowy supremacy, claimed by the one house as descendants of Brian Boroimhe and by the other as heirs of Malachi II. and of his great ancestor Niall.

The social and political system of Ireland was powerless either to expel or to absorb the foreign element thus introduced within its borders. Not only was such an union of the two peoples as had at last been effected in England simply impossible in Ireland; the Irish Danelaw was parted from its Celtic surroundings by barriers of race and speech, of law and custom and institutions, far more insuperable than those which parted the settlers in the “northman’s land” at the mouth of Seine from their West-Frankish neighbours. Even the Irish Church, which three hundred years before had won half England—one might add half Europe—to the Faith, had as yet failed to convert these pagans seated at her door. At the close of the tenth century the Ostmen were still for the most part heathens in fact if not in name, aliens from whatever culture or civilization might still remain in the nation around them. Meanwhile their relations with England had wholly altered in character. The final submission of the English Danelaw to Eadred carried with it the alliance of the Irish Danelaw; it seems that the Ostmen in their turn endeavoured to strengthen themselves against the attacks of the Irish princes by securing a good understanding with the English king, if not actually by putting themselves under his protection; for the fact that Eadgar coined money in Dublin[381] indicates that his authority must have been in some way or other acknowledged there. The years of the Ostmen’s struggle with Malachi and Brian Boroimhe were the years of England’s struggle with Swein and Cnut; but the two strifes seem to have been wholly unconnected; and throughout the long peace which lasted from Cnut’s final triumph until the coming of the Normans, new ties sprang up between the Ostmen and the sister-isle. Owing to their position on the sea-coast and to the spirit of merchant enterprise which was, quite as much as the spirit of military enterprise, a part of the wiking-heritage of their inhabitants, the towns of the Irish Danelaw rose fast into importance as seats of a flourishing trade with northern Europe, and above all with England through its chief seaports in the west, Bristol and Chester. The traffic was chiefly in slaves, bought or kidnapped in England to be sold to the merchants of Dublin or Waterford, and by these again to their Irish neighbours or to traders from yet more distant lands.[382] Horrible as this traffic was, however, even while filling the Irish coast-towns with English slaves it helped to foster a more frequent intercourse and a closer relation between Ostmen and Englishmen; and the shelter and aid given to Harold and Leofwine in 1151 by Dermot Mac-Maelnambo,[383] a prince of the royal house of Leinster who had acquired the sovereignty over both Leinstermen and Danes, shews that the political alliance established in Eadgar’s day had been carefully renewed by Godwine.

To these commercial and political relations was added soon afterwards an ecclesiastical tie. The conversion of the Ostmen to Christianity, completed in the early years of the eleventh century, was probably due to intercourse with their Christianized brethren in England rather than to the influence of the Irish clergy, whose very speech was strange to them; and their adoption of their neighbours’ creed, instead of drawing together the hostile races, soon introduced a fresh element into their strife. About the year 1040 the Ostmen of Dublin set up a bishopric of their own. Their first bishop, Donatus, was probably Irish by consecration if not by birth.[384] But when he died, in 1074,[385] the Ostmen turned instinctively towards the neighbouring island with which they had long been on peaceful terms, where the fruits of the warfare waged by generation after generation of wikings upon the shores of Britain were being reaped at last by Norman hands, where William of Normandy was entering upon the inheritance alike of Ælfred and of Cnut, and where Lanfranc was infusing a new spirit of discipline and activity into the Church of Odo and Dunstan. The last wiking-fleet that ever sailed from Dublin to attack the English coast—a fleet which Dermot Mac-Maelnambo, true to his alliance with their father, had furnished to the sons of Harold—had been beaten back six years before.[386] Since then Dermot himself was dead;[387] the Ostmen were once more free, subject to no ruler save one of their own choice and their own blood; with the consent of their king, Godred,[388] they chose a priest named Patrick to fill Donatus’s place, and sent him to be consecrated in England by the archbishop of Canterbury.[389] No scruples about infringing the rights of the Irish bishops were likely to make Lanfranc withhold his hand. At the very moment when the Ostmen’s request reached him, he had just been putting forth against the archbishop of York a claim to metropolitical jurisdiction over the whole of the British isles, founded on the words of S. Gregory committing “all the bishops of the Britains” to S. Augustine’s charge.[390] He therefore gladly welcomed an opportunity of securing for the authority of his see a footing in the neighbour-isle. He consecrated Patrick of Dublin and received his profession of obedience;[391] and for the next seventy-eight years the bishops of Dublin were suffragans not of Armagh but of Canterbury. When in 1096 the Ostmen of Waterford also chose for themselves a bishop, they too sought him beyond the sea; an Irishman, or more probably an Ostman by birth, a monk of Winchester by profession, Malchus by name, he was consecrated by S. Anselm and professed obedience to him as metropolitan.[392]