The first Viking raids took place in Ireland in 795 AD when the monastery
on Lambay Island near Dublin was attacked. In the years that followed
the Vikings attacked monasteries and settlements all over Ireland. In these
raids everything of value was stolen, buildings were set on fire and people
were killed or taken away as slaves. The people felt great terror when they
heardstories about these raids. They only felt safe when storms raged at sea.
As he listened to a howling wind one Irish monk wrote

To protect themselves, their valuables and the people who lived beside monasteries the monks built strong stone towers like this one at Clonmacnoise.

Later, some Vikings began to live in Ireland.
Some settled on land which was vacant.
Others made slaves of the local people and took control of their lands.
When they had done so the Vikings built forts with high, strong walls to protect themselves.
Viking forts were built at the mouths of the rivers Liffey,Slaney, Suir, Lee and Shannon.
The towns of Dublin, Wexford, Waterford,Cork and Limerick grew from these forts.
In their new homelands in Ireland most Viking settlers continued to live as farmers, traders and craft workers,but some also went a-Viking.
The Vikings in Ireland traded with people who lived outside their forts.
They also sailed across the Irish Sea to trade with Viking towns in Britain.
The Vikings of Dublin minted coins and had accurate weighing scales to help
them in this work. Some Irish people quickly learned the trading skills of the Vikings.Others became better weavers, carpenters and blacksmiths by studying
the skills of the Viking craft workers.