These Caledonians appear to have been divided into a number of tribes or clans, having little or no political connection, and almost constantly at war among themselves. It was only when a foreign foe threatened their much-prized freedom that a sense of danger forced them to unite for a time under the command of a military leader. Some writers, on the authority of Ptolemy of Alexandria, but chiefly on that of the pseudo-Richard of Cirencester,[3] give a list of the various tribes which, during the Roman period, inhabited North Britain, and define the locality which each occupied with as much exactness as they might do a modern English county. “There was one thing,” says Tacitus, “which gave us an advantage over these powerful nations, that they never consulted together for the advantage of the whole. It was rare that even two or three of them united against the common enemy.” Their whole means of subsistence consisted in the milk and flesh of their flocks and the produce of the chase. They lived in a state almost approaching to nudity; but whether from necessity or from choice cannot be satisfactorily determined. Dio represents the Caledonians as being naked, but Herodian speaks of them as wearing a partial covering. They appear, at all events, if the stone dug up at Blackness in the year 1868 (see p. 11), be taken as an authority, to have gone naked into battle. Their towns, which were few, consisted of huts covered with turf or skins, and for better security they were erected in the centre of some wood or morass. “What the Britons call a town,” says Cæsar, “is a tract of woody country surrounded by a vallum and ditch, for the security of themselves and cattle against the incursions of an enemy; for, when they have enclosed a very large circuit with felled trees, they build within it houses for themselves, and hovels for their cattle.”[4] Notwithstanding, perhaps owing to the scantiness of their covering, which left their bodies exposed to the rigour of a cold and variable climate, the Caledonians were a remarkably hardy race, capable of enduring fatigue, cold, and hunger to an extent which their descendants of the present day could not encounter without risk of life. They were decidedly a warlike people, and are said, like the heroes of more ancient times, to have been addicted to robbery. The weapons of their warfare consisted of small spears, long broadswords, and hand daggers; and they defended their bodies in combat by a small target or shield,--all much of the same form and construction as those afterwards used by their posterity in more modern times. It would appear from the stone above referred to that the shields of the Caledonians were oblong, with a boss in the centre, and their swords short and pointed,--not long and blunt, as represented by Tacitus. The use of cavalry appears not to have been so well understood among the Caledonians as among the more southern tribes; but in battle they often made use of cars, or