The latter were probably the followers of the newly elected and final King of the Foreigners of Munster Harald Ivarsson, 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.
A.D. 977: Brian, son of Kennedy, marched at the head of an army to Ibh-Fighenti, where he was met by Donovan, dynast of that territory, in conjunction with Auliff, king of the Danes of Munster.
Brian gave them battle, wherein Auliff and his Danes, and Donovan and his Irish forces, were all cut off.One final source, now lost but used by John Collins of Myross in the late 18th or early 19th century, reports:[3] Donovan, who was well acquainted with the personal abilities and spirit of Brian, Mahon's brother, who now succeeded him as king of North Munster, took into his pay, besides his own troops, fifteen hundred heavy-armed Danes, commanded by Avlavius, a Danish soldier of great experience.
Brian, in the Spring of 976[978], entered Kenry, where, at Crome, he gave battle, in which Donovan, Avlavius, and their party, were cut to pieces.Croom Castle was in fact a principal fortress of the O'Donovan family in the 12th century but it is unknown how early they came into possession of the stretch of the River Maigue on which it is located.