For a thousand years no foreign host had settled in Erin. But the times of peace were ended. About 800 A.D. the Irish suffered their first invasion.

The Teutonic peoples, triumphant conquerors of the land, had carried their victories over the Roman Empire to the edge of the seas that guarded Ireland. But fresh hordes of warriors were gathering in the north, conquerors of the ocean. The Scandinavians had sailed out on “the gulf’s enormous abyss, where before their eyes the vanishing bounds of the earth were hidden in gloom.” An old English riddle likened the shattering iceberg swinging down from Arctic waters to the terror of the pirate’s war-ship—the leader on the prow as it plunged through the sea, calling to the land, shouting as he goes, with laughter terrible to the earth, swinging his sharp-edged sword, grim in hate, eager for slaughter, bitter in the battle-work. They came, “great scourers of the seas—a nation desperate in attempting the conquest of other realms.”

The Scandinavian campaigns of the ocean affected Ireland as no continental wars for the creation or the destruction of the Roman Empire had done. During two hundred years their national life, their learning, their civilisation, were threatened by strangers. The social order they had built up was confronted with two new tests—violence from without, and an alien population within the island. We may ask how Irish civilisation met the trial.

The Danes fell on all the shores of England from the Forth to the Channel, the land of the Picts northward, Iona and the country of the Scots to the west, and Bretland of the Britons from the Clyde to the Land’s End: in Ireland they sailed up every creek, and shouldering their boats marched from river to river and lake to lake into every tribeland, covering the country with their forts, plundering the rich men’s raths of their cups and vessels and ornaments of gold, sacking the schools and monasteries and churches, and entering every great king’s grave for buried treasure. Their heavy iron swords, their armour, their discipline of war, gave them an overwhelming advantage against the Irish with, as they said, bodies and necks and gentle heads defended only by fine linen. Monks and scholars gathered up their manuscripts and holy ornaments, and fled away for refuge to Europe.

These wars brought a very different fate to the English and the Irish. In England, when the Danes had planted a colony on every inlet of the sea (c. 800), they took horse and rode conquering over the inland plains. They slew every English king and wiped out every English royal house save that of Wessex; and in their place set up their own kings in Northumbria and East Anglia, and made of all middle England a vast “Danelaw” a land ruled by Danish law, and by confederations of Danish towns. At the last Wessex itself was conquered, and a Danish king ruled over all England (1013). In Ireland, on the other hand, the invincible power of the tribal system for defence barred the way of invaders. Every foot of land was defended; every tribe fought for its own soil. There could be no subjection of the Irish clans except by their extermination. A Norwegian leader, Thorgils, made one supreme effort at conquest. He fixed his capital at Armagh and set up at its shrine the worship of Thor, while his wife gave her oracles from the high altar of Clonmacnois on the Shannon, in the prophetess’s cloak set with stones to the hem, the necklace of glass beads, the staff, and the great skin pouch of charms. But in the end Thorgils was taken by the king of Meath and executed, being cast into Loch Nair. The Danes, who held long and secure possession of England, great part of Scotland, and Normandy, were never able to occupy permanently any part of Ireland more than a day’s march from the chief stations of their fleets. Through two hundred years of war no Irish royal house was destroyed, no kingdom was extinguished, and no national supremacy of the Danes replaced the national supremacy of the Irish.

The long war was one of “confused noise and garments rolled in blood.” Ireland, whether they could conquer it or not, was of vast importance to the Scandinavians as a land of refuge for their fleets. Voyagers guided their way by the flights of birds from her shores; the harbours of “the great island” sheltered them; her fields of corn, her cattle driven to the shore for the “strand-hewing,” provisioned their crews; her woods gave timber for shipbuilding. Norwegians and Danes fought furiously for possession of the sea-ports, now against the Irish, now against each other. No victory or defeat counted beyond the day among the shifting and multiplying fleets of new marauders that for ever swarmed round the coasts—emigrants who had flung themselves on the sea for freedom’s sake to save their old laws and liberties, buccaneers seeking “the spoils of the sea,” sea-kings roaming the ocean or gathering for a raid on Scotland or on France, stray companies out of work or putting in for a winter’s shelter, boats of whale-fishers and walrus-killers, Danish hosts driven out of England or of Normandy. As “the sea vomited up floods of foreigners into Erin so that there was not a point without a fleet,” battle swung backwards and forwards between old settlers and new pirates, between Norsemen and Danes, between both and the Irish.

But the Scandinavians were not only sea-rovers, they were the greatest merchants that northern Europe had yet seen. From the time of Charles the Great to William the Conqueror, the whole commerce of the seas was in their hands. Eastward they pushed across Russia to the Black Sea, and carried back the wares of Asia to the Baltic; westward they poured along the coasts of Gaul by the narrow seas, or sailed the Atlantic from the Orkneys and Hebrides round the Irish coast to the Bay of Biscay. The new-made empire of Charles the Great was opening Europe once more to a settled life and the possibilities of traffic, and the Danish merchants seized the beginnings of the new trade. Ireland lay in the very centre of their seaways, with its harbours, its wealth, and its traditional commerce with France. Merchants made settlements along the coasts, and planted colonies over the inland country to supply the trade of the ports. They had come to Ireland for business, and they wanted peace and not war. They intermarried with the Irish, fostered their children, brought their goods, welcomed Irish poets into their forts, listening to Irish stories and taking new models for their own literature, and in war they joined with their Irish neighbours. A race of “Gall-Gaels,” or “foreign Irish,” grew up, accepted by the Irish as of their community. Between the two peoples there was respect and good-will.

The enterprise of the sea-rovers and the merchant settlers created on Irish shores two Scandinavian “kingdoms”—kingdoms rather of the sea than of the land. The Norsemen set up their moot on the Mound over the river Liffey (near where the Irish Parliament House rose in later days), and there created a naval power which reached along the coast from Waterford to Dundalk. The Dublin kingdom was closely connected with the Danish kingdom of Northumbria, which had its capital at York, and formed the common meeting-ground, the link which united the Northmen of Scandinavia and the Northmen of Ireland. A mighty confederation grew up. Members of the same house were kings in Dublin, in Man, and in York. The Irish Channel swarmed with their fleets. The sea was the common highway which linked the powers together, and the sea was held by fleets of swift long-ships with from ninety to a hundred and fifty rowers or fighting men on board. Dublin, the rallying-point of roving marauders, became the centre of a wide-flung war. Its harbour, looking east, was the mart of the merchant princes of the Baltic trade: there men of Iceland and of Norway landed with their merchandise or their plunder.

“Limerick of the swift ships,” “Limerick of the riveted stones,” the kingdom lying on the Atlantic was a rival even to Dublin; kings of the same house ruled in Limerick and the Hebrides, and their fleets took the way of the wide ocean; while Norse settlements scattered over Limerick, Kerry and Tipperary, organised as Irish clans and giving an Irish form to their names, maintained the inland trade. Other Munster harbours were held, some by the Danes, some by the Irish.

The Irish were on good terms with the traders. They learned to build the new ships invented by the Scandinavians where both oars and sails were used, and traded in their own ports for treasures from oversea, silken raiment and abundance of wine. We read in 900 of Irishmen along the Cork shores “high in beauty, whose resolve is quiet prosperity,” and in 950 of “Munster of the great riches,” “Munster of the swift ships.”

On the other hand, the Irish never ceased from war with the sea-kings. From the time of Thorgils, high-kings of Tara one after another led the perpetual contest to hold Ireland and to possess Dublin. They summoned assemblies in north and south of the confederated chiefs. The Irish copied not only the Scandinavian building of war-ships, but their method of raising a navy by dividing the coast into districts, each of which had to equip and man ten ships, to assemble at the summons for the united war-fleet. Every province seems to have had its fleet. The Irish, in fact, learned their lesson so well that they were able to undertake the re-conquest of their country, and become leaders of Danish and Norse troops in war. The spirit of the people rose high. From 900 their victories increased even amid disaster. Strong kings arose among them, good organisers and good fighters, and for a hundred years one leader followed hard on another. In 916, Niall, king of Tara, celebrated once more the assembly of Telltown, and led southern and northern O’Neills to the aid of Munster against the Gentiles, directing the men of Leinster in the campaign—a gallant war. Murtagh, king of Ailech or Tirconnell, smote the Danes at Carlingford and Louth in 926, a year of great danger, and so came victorious to the assembly at Telltown. Again, in 933, he defeated the “foreigners” in the north, and they left two hundred and forty heads, and all their wealth of spoils. In 941 he won his famous name, “Murtagh of the Leather Cloaks,” from the first midwinter campaign ever known in Ireland, “the hosting of the frost,” when he led his army from Donegal, under shelter of leather cloaks, over lakes and rivers frozen by the mighty frost, round the entire circuit of Ireland. Some ten years later, Cellachan, king of Cashel, took up the fight; with his linen-coated soldiers against the mail-clad foreigners, he swept the whole of Munster, capturing Limerick, Cork, Cashel and Waterford, and joining their Danish armies to his own troops; till he closed his campaign by calling out the Munster fleet from Kinsale to Galway bay, six or seven score of them, to meet the Danish ships at Dundalk. The Norsemen used armour, and rough chains of blue iron to grapple the enemies’ ships, but the Irish sailors, with their “strong enclosures of linen cloth,” and tough ropes of hemp to fling over the enemies’ prows, came off victorious. According to the saga of his triumph, Cellachan called the whole of Ireland to share in the struggle for Irish freedom, and a fleet from Ailech carried off plunder and booty from the Hebrides. He was followed by Brian Boru. “Ill luck was it for the Danes when Brian was born,” says the old saga, “when he inflicted not evil on the foreigners in the day time he did it in the next night.” From beyond the Shannon he led a fierce guerrilla war. Left with but fifteen followers alive, sleeping on “hard knotty wet roots,” he still refused to yield. “It is not hereditary to us,” he said, “to submit.” He became king of Munster in 974, drove out the Danish king from Dublin in 998, and ruled at last in 1000 as Ardri of Ireland, an old man of sixty or seventy years. In 1005 he called out all the fleets of the Norsemen of Dublin, Waterford, Wexford, and of the men of Munster, and of almost all of the men of Erin, such of them as were fit to go to sea, and they levied tribute from Saxons and Britons as far as the Clyde and Argyle.

A greater struggle still lay before the Irish. Powerful kings of Denmark, in the glory of success, began to think of their imperial destiny; and, to round off their states, proposed to create a Scandinavian empire from the Slavic shores of the Baltic across Denmark, Norway, England and Ireland, to the rim of the Atlantic, with London as the capital. King Sweyn Forkbeard, conqueror of all England, was acknowledged in 1018 its king. But the imperial plan was not yet complete. A free Irish nation of men who lived, as they said, “on the ridge of the world”—a land of unconquered peoples of the open plains and the mountains and the sea, left the Scandinavian empire with a ragged edge out on the line of the Atlantic commerce. King Cnut sent out his men for the last conquest. A vast host gathered in Dublin bay “from all the west of Europe,” from Norway, the Baltic islands, the Orkneys, Iceland, for the landing at Clontarf. From sunrise to sunset the battle raged, the hair of the warriors flying in the wind as thick as the sheaves floating in a field of oats. The Scandinavian scheme of a northern empire was shattered on that day, when with the evening floodtide the remnant of the broken Danish host put to sea. Brian Boru, his son, and his grandson lay dead. But for a hundred and fifty years to come Ireland kept its independence. England was once again, as in the time of the Roman dominion, made part of a continental empire. Ireland, as in the days of Rome, still lay outside the new imperial system.

At the end, therefore, of two hundred years of war, the Irish emerged with their national life unbroken. Irish kingdoms had lived on side by side with Danish kingdoms; in spite of the strength of the Danish forces, the constant irruptions of new Danes, and the business capacity of these fighters and traffickers, it was the Irish who were steadily coming again to the top. Through all perils they had kept their old order. The high-kings had ruled without a break, and, except in a few years of special calamity, had held the national assemblies of the country at Telltown, not far from Tara. The tribesmen of the sub-kingdoms, if their ancient place of assembly had been turned into a Danish fort, held their meeting in a hidden marsh or wood. Thus when Cashel was held by the Norsemen, the assembly met on a mound that rose in the marshy glen now called Glanworth. There Cellachan, the rightful heir, in the best of arms and dress, demanded that the nobles should remember justice, while his mother declared his title and recited a poem. And when the champions of Munster heard these great words and the speech of the woman, the tribes arose right readily to make Cellachan king. They set up his shout of king, and gave thanks to the true magnificent God for having found him. The nobles then came to Cellachan and put their hands in his hand, and placed the royal diadem round his head, and their spirits were raised at the grand sight of him.

Throughout the wars, too, the tribes had not lost the tradition of learning. King Ælfred has recorded the state of England after the Danish wars; he could not bethink him of a single one south of the Thames who could understand his ritual in English, or translate aught out of Latin, and he could hear of very few north of the Thames to the Humber, and beyond the Humber scarce any, “so clean was learning decayed among the English folk.” But the Irish had never ceased to carry on schools, and train men of distinguished learning. Clonmacnois on the Shannon, for example, preserved a truly Irish culture, and between its sackings trained great scholars whose fame could reach to King Ælfred in Wessex, and to Charles the Great in Aachen. The Irish clergy still remained unequalled in culture, even in Italy. One of them in 868 was the most learned of the Latinists of all Europe. Another, Cormac, king and bishop (†905), was skilled in Old-Irish literature, Latin, Greek, Hebrew, Welsh, Anglo-Saxon and Norse—he might be compared with that other great Irishman of his time, John Scotus, whom Charles the Bald had made head of his school. Irish teachers had a higher skill than any others in Europe in astronomy, geography and philosophy. Side by side with monastic schools the lay schools had continued without a break. By 900 the lawyers had produced at least eighteen law-books whose names are known, and a glossary. A lay scholar, probably of the ninth century, compiled the instructions of a king to his son—”Learning every art, knowledge of every language, skill in variegated work, pleading with established maxims”—these are the sciences he recommends. The Triads, compiled about the same time, count among the ornaments of wisdom, “abundance of knowledge, a number of precedents.” Irish poets, men and women, were the first in Europe to sing of Nature—of summer and winter, of the cuckoo with the grey mantle, the blackbird’s lay, the red bracken and the long hair of the heather, the talk of the rushes, the green-barked yew-tree which supports the sky, the large green of an oak fronting the storm. They sang of the Creation and the Crucifixion, when “dear God’s elements were afraid”; and of pilgrimage to Rome—”the King whom thou seekest here, unless thou bring Him with thee thou dost not find”; of the hermit’s “shining candles above the pure white scriptures … and I to be sitting for a while praying God in every place”; of the great fidelities of love—”the flagstone upon which he was wont to pray, she was upon it until she died. Her soul went to heaven. And that flagstone was put over her face.” They chanted the terror of the time, the fierce riders of the sea in death-conflict with the mounting waves: “Bitter is the conflict with the tremendous tempest”—”Bitter is the wind to-night. It tosses the ocean’s white hair; I do not fear the fierce warriors of Norway coursing on the Irish sea to-night.” And in their own war of deliverance they sang of Finn and his Fiana on the battlefield, heroes of the Irish race.

Even the craftsmen’s schools were still gathered in their raths, preserving from century to century the forms and rules of their art; soon after the battle of Clontarf we read of “the chief artificer of Ireland.” The perfection of their art in enamel and gold work has been the wonder of the old and of the modern world. Many influences had come in—Oriental, Byzantine, Scandinavian, French—and the Irish took and used them all, but their art still remained Gaelic, of their native soil. No jeweller’s work was ever more perfect than the Ardagh chalice of the ninth or tenth century, of pure Celtic art with no trace of Danish influence. The metal-workers of Munster must have been famous, from the title of “king Cellachan of the lovely cups”; and the golden case that enclosed the Gospel of Columcille in 1000 was for its splendour “the chief relic from the western world.” The stone-workers, too, carried on their art. There were schools of carvers eminent for skill, such as that of Holy Island on Lough Derg. One of the churches of Clonmacnois may date from the ninth century, five others from the tenth; finely sculptured gravestones commemorated saints and scholars; and the high-cross, a monolith ten feet high set up as a memorial to king Flann about 914, was carved by an Irish artist who was one of the greatest sculptors of northern Europe.

The temper of the people was shown in their hero-king Brian Boru, warrior and scholar. His government was with patience, mercy and justice. “King Brian thrice forgave all his outlaws the same fault,” says a Scandinavian saga, “but if they misbehaved themselves oftener, then he let them be judged by the law; and from this one may mark what a king he must have been.” “He sent professors and masters to teach wisdom and knowledge, and to buy books beyond the sea and the great ocean, because the writings and books in every church and sanctuary had been destroyed by the plunderers; and Brian himself gave the price of learning and the price of books to every one separately who went on this service. Many churches were built and repaired by him, bridges and roads were made, the fortresses of Munster were strengthened.”

Such was the astonishing vitality of learning and art among the Irish. By their social system the intellectual treasures of the race had been distributed among the whole people, and committed to their care. And the Irish tribes had proved worthy guardians of the national faith. They had known how to profit by the material skill and knowledge of the Danes. Irishmen were willing to absorb the foreigners, to marry with them, and even at times to share their wars. They learned from them to build ships, organise naval forces, advance in trade, and live in towns; they used the northern words for the parts of a ship, and the streets of a town. In outward and material civilisation they accepted the latest Scandinavian methods, just as in our days the Japanese accepted the latest Western inventions. But in what the Germans call culture—in the ordering of society and law, of life and thought, the Irish never abandoned their national loyalty. During two centuries of Danish invasions and occupations the Gaelic civilisation had not given way an inch to the strangers.