Brian Boru was born around 940 in Killaloe and together with a group of soldiers, he lived in the hills of Munster and attacked Norse settlements. Combining with his brother Mahon's forces they triumphed and over-whelmed the Vikings in Munster. However, Brian succeeded his brother and step by step he established himself in the Kingship of Munster. In time Brian became the "Ard Ri", or high king of Ireland claiming the monarchy of the whole Gaelic race.
The Vikings returned and along with the Earl of Orkney, attacked and were defeated by Brian at the Battle at Clontarf in 1014. However, as the Vikings were retreating, one of their leaders, Bothair, murdered Brian. Ireland was never again to have a king to control the entire island. His headquarters was in Killaloe and the remains of his ringfort are on the shores of Lough Derg
Brian Ború's Fort
A large ringfort stood, with a high, stone-lined embankment and a very wide outer ditch, built around the 10th century. Brian Ború lived here for a time, showing how important the lake was as a highway for commerce and war and a place where tribes paid tribute in the form of cattle. Brian's armies sailed to their battles along Lough Derg and the Shannon. Stone Age people also lived around here and over 800 of their axes and tools have been found.