During the later years of Alexander the Upright, his eldest son Kenneth Mackenzie, who was known as "Kenneth of the Battle," led the clan in the many contests in which it was engaged. Hector Roy usually assisted his brother Kenneth in warfare. He took a leading part in the celebrated battle of Park, which gave Kenneth his appellation. It seems that Kenneth of the Battle had married Margaret, daughter of John Macdonald of Islay, who laid claim not only to the lordship of the Isles, but also to the earldom of Ross. One Christmas eve Kenneth imagined himself, with some reason, to have been insulted by Alexander Macdonald, nephew and heir of John of Islay. In revenge for the insult Kenneth sent his wife (whom he did not love) back to Alexander, who was her cousin. The lady was blind of an eye, and she was sent away mounted on a one-eyed pony, accompanied by a one-eyed servant and followed by a one-eyed dog. The result was that John Macdonald of Islay determined on a great expedition to punish the Mackenzies. He mustered his followers in the Isles, and his relatives of Moidart and Ardnamurchan, to the number of three thousand warriors. Kenneth called out the clan Mackenzie, and strongly garrisoned Eileandonain Castle. Macdonald and his nephew Alexander marched to Inverness, reduced the castle there, left a garrison in it, and then plundered the lands of the sheriff of Cromarty. They next marched to Strathconan, ravaged the lands of the Mackenzies, put some of the inhabitants to the sword, and burned Contin church one Sunday morning, together with the aged people, women and children, and the old priest, who were worshipping in the church at the time. Kenneth Mackenzie sent his aged father, Alexander the Upright, from Kinellan, where he was residing, to the Raven's Rock above Strathpeffer, and himself led his men, numbering only six hundred, to the moor still known as Blar na Pairc. The Macdonalds came to the moor to meet him. Between the two forces lay a peat moss, full of deep pits and deceitful bogs. Kenneth had his own brother Duncan, and his half-brother Hector Roy, with him. By the nature of the ground Kenneth perceived that Macdonald could not bring all his forces to the attack at once. He directed his brother Duncan with a body of archers to lie in ambush, whilst he himself advanced across the moss, being able from his knowledge of the place to avoid its dangers. The van of the enemy's army charged furiously, and Kenneth, according to his pre-arranged plan, at once retreated, so that the assailants following him became entangled in the moss. Duncan Mackenzie then opened fire from his ambush on the foe both in flank and rear, slaughtering most of those who had entered the bog. Kenneth now charged with his main body, and Macdonald's forces, thrown into confusion by the stratagem, were after a desperate battle completely routed. Kenneth was attacked by Gillespie, one of Macdonald's lieutenants, and slew him in single combat.