The rampart from the mouth of the Tyne to the Solway is referred to the reign of Adrian; the conversion of Agricola's line of forts into a continuous wall to that of Aurelius Antoninus. These boundaries give us two areas. North of the Antonine frontier the Roman power was never consolidated, although the eastern half was occasionally traversed by active commanders like the Emperor Severus. It was the county of the Caledonians and Mæatæ. Between the frontier of Agricola and the rampart of Adrian, the occupation was less incomplete. Incomplete, however, it was; even when, in the fourth century, it was made a province by Theodosius, and in honour of the Emperor of Valens, called Valentia. A.D. 211, Severus, after strengthening the Antonine fortifications, dies at York; his reign being an epoch of some importance in the history of Roman Britain. In the first place, it is only up to this reign that our authorities are at all satisfactory. Cæsar, Tacitus, and Dio Cassius, have hitherto been our guides. For the next eighty years, however, we shall find no cotemporary historian at all, and when our authorities begin again, the first will be one of the worthless writers of the Panegyrics. In the next place, the great divisions of the Britannic populations have hitherto been but two--the Britons proper and the Caledonians. The next class of writers will complicate the ethnology by speaking of the Picts. The chief change, however, is that in the British population itself. The contest, except on the Welsh and Scotch frontiers, is no longer between the Roman invader and the British native; but between Britain as a Romano-Britannic province, and Rome as the centre and head of the empire: in other words, the quarrels with the mother-country replace the wars against the aborigines. This, however, is part of the civil history of Rome, rather than the natural history of Britain. The contests of Albinus against Severus, and of Proculus and Bonosus against Probus, are the earliest instances of the attempts upon the Imperial Purple from these quarters; attempts which give us the measure of the extent to which the island was Roman rather than Keltic--at least in respect to its political history. Bonosus, himself, had British blood in his veins although born in Spain, for his mother was a Gaul; but as he is called "Briton in origin," we may infer that his father was from our own island. Probus allowed the Britons the privilege of _growing vines and of making wine_.