The Vikings, also known as the Norse, began raiding Ireland in the late 8th century and continued to do so for several centuries. The Vikings targeted monasteries and coastal settlements, and their attacks were characterised by their brutality and violence. The Vikings would often kill or enslave the inhabitants, and would burn and loot the settlements.
The Vikings established a number of settlements in Ireland, including Dublin, Wexford, Waterford, and Limerick. These settlements served as trading posts and bases for further raids. Over time, the Vikings intermarried with the Irish and became a part of Irish society, and many Irish kings even employed Viking mercenaries in their armies. The Vikings also played a role in the formation of the cities of Dublin and Limerick, which became important trading centers.
The Vikings also left a lasting impact on Irish culture, with many words and names from the Old Norse language being adopted into the Irish language, such as "skald" (poet) and "haug" (mound). They also introduced new technology and ideas, such as the longship, which was used for trade and raids, and the concept of a centralised government.
The Viking presence in Ireland gradually declined in the late 11th and early 12th centuries, as the Irish kings strengthened their power and the Vikings turned their attention to other areas. Today, the Viking influence on Ireland can still be seen in place names, archaeology and some aspects of Irish culture.