The Battle of Cathair Cuan refers to a perhaps extended conflict fought in or between 977 and 978, or simply to a single battle in one or the other year, in Munster in Ireland. Attacking were Brian Bóruma and the Dál gCais, while defending were Donnubán mac Cathail and the remainder of the royal army of Norse Limerick. The last were probably the followers of the newly elected and final King of the Foreigners of Munster Aralt mac Ímair, son of the recently slain Ivar of Limerick, although it is possible Donnubán was in overall command. Brian and the Dál gCais were victorious, with the result that the Limerick lordship and its territories were decisively lost to the Gaels until the Norman invasion of Ireland. Much had already been lost to the Dál gCais by 977, probably including the great dú