As an acknowledgment of his authority all the clansmen paid calpe or tribute to the chief, and when outsiders sometimes inhabitants of a conquered district, or members of a "broken" clan, a clan without a head—attached themselves to a tribe, they usually came under a bond of manrent for offence and defence, and agreed to pay the calpe to their adopted chief. If a clansman occupied more than an eighth part of a davach of land, he also paid the chief a further duty, known as herezeld. The fundamental difference between the clan system of society and the feudal system which was destined to supersede it, was that the authority of the clan chief was based on personal and blood relationship, while that of the feudal superior is based upon tenure of land.

Of the origin of the Highland costume not much Is known. The kilt is one of the primitive garments of the world; it is one of the healthiest and probably the handsomest, and there can be no question that for the active pursuits of the mountaineer it is without a rival. In its original form, as the belted plaid, it afforded ample protection in all weathers, while leaving the limbs absolutely free for the most arduous exertions. The earliest authentic mention of the kilt appears to be that in the Norse history of Magnus Barefoot, with whom Malcolm Canmore made his famous treaty. According to that document, written about the year 1097, Magnus, on returning from his conquest of the Hebrides, adopted the dress in use there, and went about bare-legged, having a short tunic and also an upper garment, "and so men called him Barefoot." Next, in the fifteenth century is the notice by John Major, the historian, who mentions that the Highland gentlemen of his day "wore no covering from the middle of the thigh to the foot, clothing themselves with a mantle instead of an upper garment, and a shirt dyed with saffron."

As for the tartan, in Miss Donaldson’s Wanderings in the Highlands and Islands, a proposition is made that the numbers of colours employed had a relation to the rank of the wearer that eight colours were accorded to the service of the altar, seven to the king, and so on in diminishing number to the single dyed garment of the cumerlach or serf. In view, however, of the fact that all the members of a clan wear the same tartan, and that the tartans of some of the greatest clans contain but a small number of colours, such a theory obviously will not bear examination. The earliest costumes of the clansmen appear to have been not of tartan at all, but of plain colour, preferably saffron. Certain early references, like that of Aldhelm, Bishop of Sherborne in 970, and that of Ossian when describing a Caledonian woman as appearing in robes "like the bow of the shower," are by no means conclusive as referring to tartan. As variety came to be desired, each clan would use the natural dyes most easily procured in its district, and the easiest pattern to weave was one of simple warp and woof. By and by a clansman would come to be identified by the local pattern he wore, and before long that pattern would come to be known as the tartan of his clan. Whether or not this describes the actual origin of the Highland tartans, there can be no question as to their suitability for the purposes of the hunter and the warrior, to whom it was important to be as little conspicuous as possible on a moor or mountain-side. It was also of value to the clansmen in battle, who required readily to distinguish between friend and foe.