They became enmeshed in Irish politics.  They would learn the lesson of all conquerors here. The longer you stay around, the more likely you are to become drawn into the quarrels of your neighbours. 

 

This was a country where local Gaelic kings were fighting for land and supremacy. They did so as power was being centralised across Europe. Small kingdoms were eaten up by the leaders of emerging dynasties. In northern France, Rollo the Viking had founded the Norman Empire. In England, power was consolidating around the house of Wessex. 

 

Such change could hardly have escaped the attention of an ambitious Irish king. This new leader was a man with the ruthlessness and energy to humble kingdoms. He stormed the strongholds of his enemies, and in 4 years, was able to come here to the Rock of Cashel and proclaim himself king of all Munster. He demanded tributes from the defeated of wine and gold and the most precious commodity of the age, cattle. They called him Brian of the Cattle Tributes. In the Irish, Brian Boru.