The main facts, however, are reliable: Mahoun was entrapped in some way to the house of Donovan, and there he was basely murdered, in violation of the rights of hospitality, and in defiance of the safe-conduct of the bishop, which he secured before his visit.
The traitors gained nothing by their treachery except the contempt of posterity.

Brian was not slow in avenging his brother.

"He was not a stone in place of an egg, nor a wisp of hay in place of a club; but he was a hero in place of a hero, and valour after valour."[211] Public opinion was not mistaken in its estimate of his character.

Two years after the death of Mahoun, Brian invaded Donovan's territory, drove off his cattle, took the fortress of Cathair Cuan, and slew Donovan and his Danish ally, Harolt.

He next proceeded to settle accounts with Molloy.