Ireland had known no invaders since prehistoric times. The Vikings, who arrived quite suddenly at the end of the eighth century, sent shock waves through a society in which Christianity had been left to organize itself, exercise its influence, and cultivate its artistic treasures largely undisturbed for more than three centuries.

Marauding seafarers from Norway and Denmark brought ruin and confusion, but they also made a positive contribution to subsequent Irish history in founding the first towns. They tied the island to a continental empire of far-flung places where the Vikings raided and traded, launching both the first large-scale outside contacts and the beginnings of commercial life. In time, like their predecessors before them, they too conformed to Ireland’s demographic pattern in assimilating with the natives, becoming Christians, and adopting the Irish language and Irish customs. Initially an independent force sitting behind the defensive walls of their coastal and riverine settlements, they began trading with the interior and soon found themselves drawn into dynastic struggles, which marked the politics of this period just as they had politics for centuries before.

The Vikings brought a nautical technology and superior weaponry, which facilitated the ability to do battle across wider territories with more deadly means. Irish royal dynasties, fewer in number but richer in resources, fought to acquire whole kingdoms, and the first efforts to claim the title of high king by actually possessing the requisite geographical territory were made. Because the stakes were higher, the clashes grew more intense, and the bitterness engendered by those who found themselves on the losing end of the ceaseless dueling stung with more lasting effect. The enmity harbored by the king of Leinster, banished from Ireland in the summer of 1166, would lead to a train of events that carried consequences for the country unlike any other.

The Era of the Viking Wars

In 795 long low-slung ships, fitted with wide, decoratively patterned sails, appeared from off the ocean’s horizon and ran their pointed bows onto the rocky beach at Iona. Warriors wearing round or horned helmets, armed with heavy swords and iron spears, rushed into the monastic village and, in a frenzied fury, ransacked the settlement, carrying away slaves and booty, including altar shrines and vessels, their surfaces glittering with the gems with which they had been so painstakingly inlaid. In the same year, seafaring raiders burned the community at Rathlin and attacked those at Inishmurray and Inishbofin.

The Vikings were bands of warriors from Scandinavia who set sail from its shores with but one purpose in mind-to seize whatever plunder they could find. The ships they manned were the most technically advanced of their time, designed by skilled Nordic craftsmen to provide the maximum in mobility. Whatever the reasons that led the Vikings to set out on their quest for riches-and they remain obscure-raiding that had begun in the Baltic Sea spread outwards from there at the end of the eighth century. over time these men from the far North (Norsemen) ranged as far east as Moscow and Constantinople and as far west as the North American continent. In the 790s fleets attacked Ireland, Britain, and France simultaneously.

Pagan farmers and fishermen and, at home, many of them dexterous craftsmen, the Vikings were the penultimate pirates. led by their kings and nobles, they are said to have delighted in destruction for destruction’s sake. Wielding their terrifying signature weapon, the broad battleaxe, raiders returned to Iona in 802 and again in 806, this time murdering 68 of the monks. The great monasteries, the centers of wealth, were the targets of attacks again and again during the first 40 years of the ninth century. fear pervaded the atmosphere wherever they roamed, for the Vikings would appear suddenly without warning at any time, ready to wreak havoc without scruple.

By 823 they had completed the circumnavigation of the Irish coast, in 824 even sacking bleak Skellig Michael. Most of the raiders to Ireland came from the fjords of Norway, and during the first decades of the 800s they never tarried long, operating as small, quick-moving forces striking in hit-and-run attacks. The Irish fought back as best they could. Monks moved to inland areas. After the raid of 806 the abbot at Iona, Cellard, carrying with him the revered relics of Columbanus, traveled with his companions 20 miles inland from the Irish coast to Kells, where they founded a new monastery. Kings from Ulster to Munster battled the invaders when they could catch up with them.

In the end, however, the search for security proved elusive. Raids intensified in the 830s, and now roving bands began moving inland. In 836 the first Viking land raids on record occurred on lands of the southern Ui Néill, and much of Connacht was also devastated. The following year the course of invasions began to change character. A mighty fleet of 60 ships appeared on the river Boyne and another 60 on the Liffey. Norsemen pillaged churches, fortresses, and farms in the Liffey valley, and they sailed up the Shannon and the Erne as well, defeating the forces of the Irish kings wherever they went. Viking ships plied the Shannon lakes in the very heart of the country. They appeared to be unbeatable. In 841, at Linn Duachaill (present-day Annagassan, County lough) and at Dublin they set up defensive bases as footholds from which to mount invasions deep into the interior. At Dublin, the Vikings wintered for the first time in 841-42, building a stockade around their ships and thus laying the foundation of the city.

In the middle of the ninth century, Vikings from Denmark began to arrive, adding another element to the mayhem. The Vikings on the scene resented the interlopers and battled them in a fighting stew that included old and new combatants both native and foreign-Viking against Viking, Viking against Irish, and Irish against Irish.

No one anywhere was safe, but Irish kings kept up running battles against the invaders. They gradually began to achieve greater success, measured both by victories in battle and by a decline in the number of attacks. In 835 the Vikings were defeated at Derry, and in 845 Mael Sechnaill mac Maéle Runaid, king of Meath, captured and drowned the Viking leader, Turgeis. fleets were still arriving in 849-51, but by a decade later the great raids were over.

That the Irish had found it difficult to resist the invaders stemmed in part from their inability to unite to meet the common threat. The peak of the Viking incursions found the Ui Néill, based at Tara in Ulster, and the Eoganacht, at Cashel in Munster, clashing for the first time on a large scale. And the Scandinavians proved more than willing to join in the local strife. The Vikings very quickly-by the mid ninth century-assumed an active role in the local inter-dynastic warfare. The first Viking-Irish alliance is recorded in 842, and accounts speak increasingly of these pacts from 850 on.

Battles followed battles both within and between kingdoms, and the power of kings waxed and waned. The Ui Néill kings at Tara built up their power gradually in the second half of the ninth century, and the Vikings in Ulster were largely brought under control. The Vikings remained strongest at Dublin, where they frequently allied with surrounding rulers.

The close of the ninth century saw a slackening in Viking activity; however, the respite proved but a brief interlude. A second period of major incursions began in the second decade of the 10th century and lasted for 25 years. The storm to come gathered force in 914 when a great fleet of ships massed in Waterford harbor. In 915 they set out to attach Munster and, later, Leinster, yet again laying waste monasteries at Cork, Aghaboe, Lismore, and elsewhere. And once again, the Irish counterattacked. Niall glundub mac Aedo (d. 919), overking of the Ui Néill, chased the Viking raiders through Munster in 917 but failed to stop them, his allies from Leinster meeting heavy defeat. He himself fell victim two years later when he and many leading aristocrats of the Ui Néill were defeated and killed by the Vikings at the Battle of Dublin. Triumphant yet again, the Norsemen, secure in their base at Dublin, set about consolidating control of outlying settlements in limerick and Waterford. By about 950 the second great wave of raids was largely over.

What effect did the Viking invasions have on Irish society? Certainly considerable death and destruction occurred. Much cultural heritage disappeared, and the number of treasures that were irretrievably lost cannot be calculated.

Yet, while life was disrupted, it was not extinguished. The Vikings, in fact, also had a very positive impact. In founding settlements, they introduced commercial activity into a society hitherto based entirely on subsistence agriculture. once settled in Ireland, the Vikings did not become farmers and fishermen; rather, they became merchants and seamen. Unlike in Britain and France where they moved inland, those in Ireland contented themselves in remaining where they had landed. from their bases that hugged the coastline at Dublin, Cork, Waterford, and on the Shannon at limerick, they built up a system of seaborne commerce that linked Ireland with markets from Scandinavia to Spain.

Dublin retained its status as the most important Viking settlement, and the town grew swiftly in engaging in a far-flung trade that made it one of the richest in Viking Europe.

Dublin, together with York in Britain, became the most important of the westernmost trading posts. Trade became so significant that a cash-based economy was introduced in 953 when the first silver coins were minted. They continued to be issued until the arrival of the Normans. In introducing commercial life to the country, the Vikings set in motion the shift of the island’s political and social fulcrum from the central midlands to east coast urban centers, a move that has endured.

Expert traders and sailors, the Vikings introduced their advanced shipbuilding skills to Ireland. Busily plying the coastal waters, the warring wayfarers imprinted their presence on the island’s fringes. Not only settlements-Waterford, Wicklow, Strangford, and Dalkey-but also islands and bays-Blaskets, Smerwick, Salters, and Selskou-carry their names.

Although settlements might suffer repeated attacks throughout the upheavals of the ninth and 10th centuries, social life, while subject to disruptions, adhered to familiar patterns. Monastic communities rebuilt or moved to other locales. Irish kings were hard pressed by Viking incursions, and several small kingdoms near Norse settlements were overwhelmed, yet the strife that had for so long characterized native society never abated. Kings continued to war with kings.

The Norse invasions and their aftermath

The first appearance of the Norsemen on the Irish coast is recorded in 795. Thereafter the Norsemen made frequent plundering raids, sometimes far inland. In 838 they seized and fortified two ports, Annagassan and Dublin, and in the 840s they undertook a series of large-scale invasions in the north of the country. These invaders were driven out by Aed Finnliath, high king from 862 to 879, but meanwhile the Norse rulers of Dublin were reaching the zenith of their power. They took Waterford in 914 and Limerick in 920. Gradually, without quite abandoning piracy, the Vikings became traders in close association with the Irish, and their commercial towns became a new element in the life of the country. The decline of Norse power in the south began when they lost Limerick in 968 and was finally effected when the Scandinavian allies of the king of Dublin were defeated by High King Brian Boru at the Battle of Clontarf in 1014.

Although the Battle of Clontarf removed the prospect of Norse domination, it brought a period of political unsettlement. High kings ruled in Ireland but almost always “with opposition,” meaning they were not acknowledged by a minority of provincial kings. The Viking invasions had, in fact, shown the strength and the weakness of the Irish position. The fact that power had been preserved at a local level in Ireland enabled a maximum of resistance to be made; and, although the invaders established maritime strongholds, they never achieved any domination comparable to their control of eastern England or northwestern France. After Clontarf they remained largely in control of Ireland’s commerce but came increasingly under the influence of neighbouring Irish kings.