Sir Hugh Kennedy of Griffen Mains dwelt then in Sutherland, having married John, Earl of Sutherland's mother, after the death of his father, Alexander, Master of Sutherland. Sir Hugh Kennedy being advertised of Mackay's coming into Sutherland, he advises with Hutcheon Murray of Abirscors, and with Gilbert Gordon of Garty, what was best to be done. They resolve to fight the enemy; and so having gathered a company of men, they overtook Mackay, unawares, beside a place called Ailtan-Beath, where they invaded him suddenly; having passed his spies unseen.
After a little skirmish the Strathnaver men fled, the booty was rescued, and John MacIan-MacAngus, one of their chieftains, was slain, with divers of the Strathnaver men. Donald Mackay, nevertheless, played the part of a good soldier; for in his flight he killed, with his own hand, one William Sutherland, who most eagerly pursued him in the chase.
The inhabitants of Sutherland and Strathnaver (in regard of Earl John's minority) did thus continually vex one another, until this Donald Mackay was apprehended and imprisoned in the Castle of Fowlis, in Ross, by commandment of the Queen Regent and the Governor, where he continued a good while in captivity.