Once the Anglo-Saxons had settled in England, they calmed down somewhat. They built towns, converted to Christianity, stopped raiding, and behaved like “civilized” people. But in the eighth century, they were attacked by another group of invaders: the Vikings.

The Vikings were Scandinavian people from Norway, Sweden, and Denmark, basically a northern version of the earlier Germanic invaders. Between 750 and 1050, Scandinavians spread all over northern Europe and into the Atlantic, establishing colonies in faraway Iceland, Greenland, and even Labrador. They were collectively called Vikings, which either comes from the Norse word vik, meaning “bay,” or the Old English word wic, meaning “camp.” Either is possible: Viking boats were often found in bays, and they set up camps across Western Europe.

The Vikings called themselves Ostmen, or “men from the east.” They were excellent sailors, and they had a reputation for raiding, stealing, and burning whatever they found in their way.

The Assault on Ireland

The Vikings first hit Ireland in 795, landing their technologically advanced warships at Lambay Island near the site of modern Dublin. From there they launched attacks up and down the coast, first concentrating their raids on the northern and western seaboards. Between 820 and 840, they ventured down rivers into the interior of the island, attacking churches for booty and captives.

The Vikings developed a quick and efficient style of hit-and-run attack. Although the Irish fought back, the Vikings were at least as ferocious as the Celts and much better armed. Also, the Irish were never unified against the Vikings; the wealth of the monasteries attracted the attention of several Irish lords, and sometimes monks found themselves under attack by their own countrymen.

A round tower dating from the Viking conquest

The monks responded by fortifying their monasteries, reinforcing wooden walls with stone and adding other defensive structures. The most famous of these fortifications were round towers, tapering stone cylinders 100 feet high that doubled as bell towers and watchtowers; a five-story staircase led up to the top.

The entrances to these towers were raised off the ground and could only be entered by climbing a ladder. When the monks were under attack, they could all climb into the tower and then pull up the ladder after themselves. Then they could climb up to the top and watch their monastery burn as they themselves slowly starved; the hope was always that the invaders would leave before that happened.

Dublin Is Founded

Eventually the Vikings stopped raiding and started settling down. They built settlements called longphorts, which were similar to naval camps. They used these encampments as bases for further attacks, but also as foundations for towns. The Vikings founded Dublin around 840, when they spent the winter moored there. The city's name comes from the words “Dubh Linn,” which means “Black Pool.” Dublin became the Vikings' chief base in Ireland, the place from which they launched raids on unconquered lands.

The Problems of Disorganization

One of the things that prevented the Irish natives from defending themselves against the Vikings' earliest onslaughts was the endless state of mild to severe warfare that they maintained against one another. They couldn't stop arguing among themselves long enough to join forces against their common invaders, nor did they have any sense of a single Irish nation.

As the Vikings became more settled, though, they became more vulnerable to attack; people without property have nothing to defend, but someone with a house and farm has to keep watch over them. Norse Vikings and Danish Vikings fought over the same Irish territory. Starting in about 850, Irish kings began to launch their own raids on the Vikings with some success. A funny thing happened around that time; Irish kings and Vikings started to form alliances to fight other Irish kings, who had their own Viking allies.

By 900, the Vikings' Irish administration (such as it was) was in complete disarray, and the invaders had turned their attention to new raids in Iceland and northern Britain. This gave the Irish a window of opportunity, and they expelled the Vikings from Dublin in 902. Many Vikings left Ireland and bothered Britain instead for a few years.

Unfortunately, it was only a brief respite for the Irish. The Vikings came back in 914, took back Dublin, Munster, and Leinster, and spent another twenty years in power. After 950 they ceased to be much of a military threat, but they stayed on in the parts of Ireland that had become their home.