Better known as "Coinneach a' Bhlair," or Kenneth of the Battle, from his prowess and success against the Macdonalds at the Battle of Park during his father's life-time. He was served heir to his predecessor and seized in the lands of Kintail at Dingwall on the 2nd of September, 1488. He secured the cognomen "Of the Battle" from the distinguished part he took in "Blar-na-Pairc" fought at a well-known spot still pointed out near Kinellan, above Strathpeffer. His father was advanced in life before Kenneth married, and as soon as the latter arrived at twenty years of age Alexander thought it prudent, with the view of establishing peace between the two families, to match Kenneth, his heir and successor, with Margaret, daughter of John Lord of the Isles and fourth Earl of Ross, and for ever extinguish their ancient feuds in that alliance. The Island chief willingly consented and the marriage was in due course solemnised. About a year after, the Earl's nephew and apparent heir, Alexander Macdonald of Lochalsh, came to Ross, and, feeling more secure in consequence of this matrimonial alliance between the family of Mackenzie and his own, took possession of Balcony House and the adjoining lands, where, at the following Christmas, he provided a great feast for his old dependants, inviting to it also most of the more powerful chiefs and barons north of the Spey, and among others, Kenneth Mackenzie, his cousin's husband. The house of Balcony being at the time very much out of repair, he could not conveniently lodge all his distinguished guests within it, and had accordingly to arrange for some of them in the outhouses as best he could.

Kenneth did not arrive until Christmas Eve, accompanied by a train of forty able bodied men, according to the custom of the times, but without his lady, which deeply offended Macdonald. Maclean of Duart had chief charge of the arrangements in the house and the disposal of the guests. Some days previously he had a disagreement with Kenneth at some games, and, on his arrival, Maclean told the heir of Kintail that, taking advantage of his connection with the family, they had taken the liberty of providing him with lodgings in the kiln. Kenneth considered this an insult, and, divining that it proceeded from Maclean's illwill to him, he instantly struck him a blow on the ear, which threw him to the ground. The servants in the house viewed this as a direct insult to their chief, Macdonald, and at once took to arms. Kenneth, though sufficiently bold, soon perceived that he had no chance to light successfully or to beat a retreat, and, noticing several boats lying on the shore, which had been provided for the transport of the guests, he took as many of them as he required, sank the rest, and passed with his followers to the opposite shore, where he remained over night in the house of a tenant, who, like a good many more in those days, had no surname, but was simply known by a patronymic. Kenneth, boiling with passion, was sorely affronted at the insult which he had received, and at being from his own house at Christmas, staying with a stranger, and off his own property. In these circumstances, he requested his host to adopt the name of Mackenzie, promising him protection in future, so that be might thus be able to say that he slept under the roof of one of his own name. The man at once consented, and his posterity were ever after known as Mackenzies.

Next morning (Christmas Day) Kenneth went to the hill above Chanonry, and sent word to the Bishop, who was at the time enjoying his Christmas with some of his clergy, that he desired to speak to him. The Bishop knowing his man's temper and the turbulent state of the times thought it prudent to comply with this request, though be considered it very strange to receive such a message on such a day, and wondered much what his visitors object could be. He soon found that Kenneth simply wanted a feu of the small piece of land on which was situated the house in which he had lodged the previous night, stating, as his reason, "lest Macdonald should brag that he had forced him on Christmas Day to lodge at another man's discretion, and not on own heritage." The Bishop, willing to oblige him probably afraid to do otherwise, and perceiving him in such a rage, at once sent for his clerk and there and then granted him a charter of the township of Cullicudden, whereupon Kenneth returned to the place and remained in it all day, lording over it as his own property.

The place was kept by him and his successors until Colin "Cam" acquired more of the Bishop's lands in the neighbourhood, and afterwards exchanged the whole with the Sheriff of Cromarty for lands in Strathpeffer.

Next day Kenneth started for Kinellan, where his father, the old chief Alexander, resided, and related to him what had taken place. His father was much grieved, for he well knew that the smallest difference between the families would revive their old grievances, and, although there was less danger since Macdonald's interest in Ross was smaller than in the past, yet he knew the clan to be a powerful one still, more so than his own, in their number of able-bodied warriors; but these considerations, strongly impressed upon the son by the experienced and aged father, only added fuel to the fire in Kenneth's bosom, which was already fiercely burning to avenge the insult offered him by Macdonald's servants. His natural impetuosity could ill brook any such insult and he considered himself wronged so much that he felt it his duty personally to retaliate and avenge it. While this was the state of his mind matters were suddenly brought to a crisis by the arrival on the fourth day of a messenger from Macdonald with a summons requesting Alexander and his son Kenneth to remove from Kinellan, with all their families, within twenty-four hours, allowing only that the young Lady Margaret, Macdonald's own cousin, might remain until she had more leisure to remove, and threatening war to the knife in case of noncompliance.

Kenneth's rage now became ungovernable, and, without consulting his father or waiting his counsel, he bade the messenger tell Macdonald that his father would remain where he was in spite of him and all his power. As for himself, he accepted no rules as to his staying or going, but Macdonald would be sure enough to hear of him wherever he was. As for Macdonald's cousin, Lady Margaret, since he had no desire to keep further peace with his family he would no longer keep his relative.

Such was the defiant message sent to young Macdonald, and immediately after its despatch, Kenneth sent away Lady Margaret, in the most ignominious manner, to Balcony House. The lady was blind of an eye, and, to insult her cousin to the utmost, he sent her back to him mounted on a one-eyed horse, accompanied by a one-eyed servant, followed by a one-eyed dog. She was in a delicate state of health, and this inhumanity grieved her so much that she never after wholly recovered. Her son, recently born, the only issue of the marriage, was named Kenneth, and to distinguish him from his father was called "Coinneach Og" or Kenneth the younger.

It appears that Kenneth had no great affection for Lady Margaret, for a few days after he sent her away he went to Lord Lovat accompanie by two hundred of his followers and besieged his house. Lovat was naturally surprised at his conduct and demanded an explanation, when he was informed by Kenneth that he came to demand his daughter Agnes in marriage now that he had no wife, having, as he told him, disposed of Lady Margaret in the manner already described. He insisted upon an immediate and favourable reply to his suit on which condition he promised to be on strict terms of friendship with the family; but, if his demand was refused he would swear mortal enmity against Lovat and his house; and, as evidence of his intention in this respect, he pointed out to his lordship that he already bad a party of his vassals outside gathering together the men, women, and goods that were nearest in the vicinity, all of whom, be declared, should "be made one fyne to evidence his resolution." Lovat, who had no particularly friendly feelings towards Macdonald of the Isles, was not at all indisposed to procure Mackenzie's friendship on the terms proposed, and considering the exigencies and danger of his retainers, and knowing full well the bold and determined character of the man he had to deal with, he consented to the proposed alliance, provided the voting lady herself was favourable. She fortunately proved submissive. Lord Lovat delivered her up to her suitor, who immediately returned borne with her, and ever after they lived together as husband and wife.