Agriculture; its deep valleys and gorges and wild moors and high peaks
oppose alike the soldier and the citizen. Behind this upland lies the
Atlantic, and an Atlantic which meant of old the reverse of what it does
to-day. To the ancients, this hill-country was the end of the world; for us—since Columbus—it is the beginning.
These physical features are reproduced plainly in the early history of Britain. It was natural that about b.c. 50-a.d. 50 southern Britain should be occupied by Keltic tribes and even families which had close kindred in Gaul, and that a lively intercourse should exist between the two. It was no less natural that, even before Rome had fully conquered Gaul, Caesar’s troops should be seen in Kent and Middlesex (b.c. 55-54) and Roman suzerainty extended over these regions; and when the annexation of Gaul was finally complete, that of Britain seemed the obvious sequel. The sequel was, indeed, delayed awhile by political causes. Augustus (b.c. 43-a.d. 14) had too much else to do: Tiberius (14-37) saw no need for it, just as he saw no need for any wars of conquest. But after 37 it became urgent. Changes in southern Britain had favoured an anti-Roman reaction there and had even perhaps produced disquiet in northern Gaul; Caligula (37-41) had made some fiasco in connexion with it; when Claudius succeeded, there was need of vigorous action and, as it chanced, the leading statesmen of the moment favoured a forward policy in many lands. The result was a well-planned and deservedly successful invasion (a.d. 43).
The details of the ensuing war of conquest do no^ here concern us. It is enough to say that the lowlands offered little resistance. In one part of them, near the south-east coast, Roman ways had become familiar since Caesar’s raids. In another part—the midlands—the population was then, as now, thin. Nowhere (despite the theories of Guest and Green) were there physical obstacles likely to delay the Roman arms. By 47 the invaders had subdued almost all the lowlands, as far west as Exeter and Shrewsbury and as far north as the Humber. Then came a pause. The difficulties of the hill-country, the bravery of the hill-tribes, political circumstances at Rome, combined not indeed to arrest but seriously to impede advance. But the decade 70-80 saw the final conquest of Wales and the first subjugation of northern England, and in the years 80-84 Agricola was able to cross the Tyne and the Cheviots and gradually advance into Perthshire. Much of the land which he overran was but imperfectly subdued and the northern part of it—everything, probably, north of the Tweed—was abandoned when he was recalled (85). Thirty years later (115-120) an in- surrection shook the whole Roman power in northern Britain, and when Hadrian had restored order, he established the frontier along a line from Tyne to Solway, which he fortified by forts and a continuous wall (about 122-124). Fifteen or twenty years later, about a.d. 140, his successor Pius, for reasons not properly recorded, made a fresh
