Brian Boru born c. 940 (near Killaloe in modern County Clare), died 1014, was king of Munster, and the most famous High King of Ireland. Born Brian Mac Cennétig (Kennedy), he was inaugurated King of Munster in 976 and High King of Ireland in 1002.

He is remembered most for defeating and driving away the Danes.

He became known as Brian of the Tributes (Boru), because he collected monies from the minor rulers of Ireland and used these to rebuild monasteries and libraries that had been destroyed during Norsemen (Viking) invasions. His fame was so great that the princes descended from him, the O'Briens, subsequently ranked as one of the chief dynastic families of the country (see Chiefs of the Name).

He was killed on Good Friday April 23, 1014 during the Battle of Clontarf against the Vikings as he prayed.