 In 1476, a secret treaty that was made by Aonghas's father, John MacDonald, with King Edward IV of England was discovered by King James III of Scotland, who then stripped MacDonald of his earldom, as well as the sheriffdoms of Nairn and Inverness, and the lordships of Kintyre and Knapdale; the King however confirmed MacDonald with the remainder of his lands and the title Lord of the Isles.It appears that Aonghas, as MacDonald's heir, was not prepared to accept this settlement.Aonghas campaigned to regain Ross and the other lost dominions.