The battle took place during a military campaign led by Ivar of Limerick into Dál gCais territory.
The only extended account of the battle, including background, mustering, and aftermath, is found in the controversial Cogad Gáedel re Gallaib.
Their success forced Ivar into a hasty coalition with Mathgamain's rivals, including the elected king Molloy of Desmond and Donovan of Hy Carbery.
In the summer of 968 Ivar and his allies gathered a large host and set about ravaging the ancestral lands of Boru and Mathgamain.
The brothers called in their supporters and marched north from Cashel to meet their enemy on the wooded plain of Sulcoit.
The Dal gCais pursued the broken army "beheading many along the way" back to Limerick and stormed into the city, ruthlessly sacking it and massacring most of the inhabitants.
One day in the year 968, Brian sent out a small raiding party to bait the Vikings by having them follow the men to where the Dál gCais were waiting.
At a small rise called Sulcoit near the modern town of Soloheadbeg Brian's men lied in wait.
The Battle of Sulcoit is the subject of the song "Born for War (The Rise of Brian Boru)", by the Irish folk metal band Cruachan Notes Bibliography