Brian Bóruma (or Brian Boru) (c. 941–1014)

King of Munster from 976 and high king of Ireland from 999. His campaigns represent the rise of Munster as a power in Ireland, symbolized by his victory over Leinster and the Dublin Norse at Glen Mama in 999. He was renowned as a builder of forts, and this may have been his most significant military legacy. He died in victory over the Vikings at Clontarf in Dublin.

Brian Bóruma is an Irish national hero, celebrated as the conqueror of the Vikings, although the Battle of Clontarf made very little difference to the Irish position in Ireland. The War of the Irish against the Foreigners, a piece of 12th-century dynastic propaganda, provides details of his campaigns from 968 to 1014, which saw him emerge as high king. He was the last high king with jurisdiction over most of Scotland.