Rob Roy was, therefore, sure of refuge in the country of the Campbells, both as having assumed their name, as connected by his mother with the family of Glenfalloch, and as an enemy to the rival house of Montrose.

The extent of Argyle's possessions, and the power of retreating thither in any emergency, gave great encouragement to the bold schemes of revenge which he had adopted.
This was nothing short of the maintenance of a predatory war against the Duke of Montrose, whom he considered as the author of his exclusion from civil society, and of the outlawry to which he had been sentenced by letters of horning and caption (legal writs so called), as well as the seizure of his goods, and adjudication of his landed property.

Against his Grace, therefore, his tenants, friends, allies, and relatives, he disposed himself to employ every means of annoyance in his power; and though this was a circle sufficiently extensive for active depredation, Rob, who professed himself a Jacobite, took the liberty of extending his sphere of operations against all whom he chose to consider as friendly to the revolutionary government, or to that most obnoxious of measures--the Union of the Kingdoms.

Under one or other of these pretexts, all his neighbours of the Lowlands who had anything to lose, or were unwilling to compound for security by paying him an annual sum for protection or forbearance, were exposed to his ravages.
The country in which this private warfare, or system of depredation, was to be carried on, was, until opened up by roads, in the highest degree favourable for his purpose.

It was broken up into narrow valleys, the habitable part of which bore no proportion to the huge wildernesses of forest, rocks, and precipices by which they were encircled, and which was, moreover, full of inextricable passes, morasses, and natural strengths, unknown to any but the inhabitants themselves, where a few men acquainted with the ground were capable, with ordinary address, of baffling the pursuit of numbers.
The opinions and habits of the nearest neighbours to the Highland line were also highly favourable to Rob Roy's purpose.