There being some variance and controversy "between Mackenzie and Donald Mac Angus of Glengarry, they were both ordered at the same meeting of Council to subscribe, within three hours after being charged, such forms of mutual assurance as should be presented to them, to endure till the 1st of May, 1603, under pain of rebellion. By warrant of the King, Kenneth is admitted a member of the Privy Council and is sworn in, in common form, on the 9th of December, 1602. On the following day he gives caution for James Dunbar of Little Suddie, and John Dunbar, Fiar of Avoch, in two hundred merks, for their relaxation by the 1st of February next from several hornings used against them. At a meeting of the Privy Council, held at Edinburgh on the 30th of September, 1605, Kenneth receives a commission to act for the King against Neil MacNeill of Barra, the Captain of Clanranald, and several other Highland and Island chiefs, who had "of late amassed together a force and company of the barbarous and rebellious thieves and limmers of the Isles," and with them entered the Lewis, "assailed the camp of his Majesty's good subjects," and "committed barbarous and detestable murders and slaughters upon them." Mackenzie is in consequence commissioned to convocate the lieges in arms and to pursue these offenders with fire and sword by sea or land, "take and slay them," or present them to their Lordships for justice, with power also to the said Kenneth to pass to the Lewis for thc relief of the subjects "distressed and grieved" by the said rebellious "lymmairis," or of prisoners in their hands, and to procure their liberty by "force or policy, as he may best have it." He is also ordered to charge the lieges within the shires of Inverness and Nairn, burgh and landward, to rise and assist him in the execution of his office, whenever he requires them, "by his precepts and proclamations." This was the beginning of Kenneth's second conquest of the Lewis. Mackenzie is, on the 2nd of June, 1607, appointed by the Privy Council, along with the Bishop of Ross, a commissioner to the Presbyteries of Tam and Ardmeanach, and on the 14th of July following, he is summoned before their Lordships to report his diligence in that matter, under pain of rebellion. Kenneth does not appear, and he is denounced a rebel. On the 30th of July he takes the oath of allegiance, along with the Earl of Wyntoun and James Bishop of Orkney, in terms of a Royal letter issued on the 2nd of June preceding imposing a special oath acknowledging the Royal Supremacy in Church and state on all Scotsmen holding any civic or ecclesiastical office.