This battle (which lasted from sunrise to sunset) pitted forces led by Brian Boru, High King of Ireland, against a Norse-Irish alliance comprising the forces of
- Sigtrygg Silkbeard, King of Dublin;
- Máel Mórda mac Murchada, King of Leinster;
and an external Viking contingent led by
- Sigurd, of Orkney; and
- Brodir of Mann.
It ended in a rout of the Viking and Leinster forces.
Although Brian's forces were victorious, Brian himself was killed, as were his son Murchad and his grandson Toirdelbach.
Leinster king Máel Mórda and Viking leaders Sigurd and Brodir were also slain.
Brian's family was temporarily eclipsed, and there was no undisputed High King of Ireland until the late 12th century.