It proved no sure defence, however, for he was shortly after murdered in a vault of the castle,---the family annals say by the MacGregors, though other accounts charge the deed upon the MacFarlanes.
This battle of Glenfruin, and the severity which the victors exercised in the pursuit, was reported to King James VI.

in a manner the most unfavourable to the clan Gregor, whose general character, being that of lawless though brave men, could not much avail them in such a case.

That James might fully understand the extent of the slaughter, the widows of the slain, to the number of eleven score, in deep mourning, riding upon white palfreys, and each bearing her husband's bloody shirt on a spear, appeared at Stirling, in presence of a monarch peculiarly accessible to such sights of fear and sorrow, to demand vengeance for the death of their husbands, upon those by whom they had been made desolate.
The remedy resorted to was at least as severe as the cruelties which it was designed to punish.

By an Act of the Privy Council, dated 3d April 1603, the name of MacGregor was expressly abolished, and those who had hitherto borne it were commanded to change it for other surnames, the pain of death being denounced against those who should call themselves Gregor or MacGregor, the names of their fathers.

Under the same penalty, all who had been at the conflict of Glenfruin, or accessory to other marauding parties charged in the act, were prohibited from carrying weapons, except a pointless knife to eat their victuals.