So in 120 the Emperor Hadrian himself arrived in Britain to study the problem, bringing with him, to replace the lost troops, Legio VI. (‘Victrix’), whose headquarters were to be at Eboracum (York) for nearly three hundred years. He decided to draw a connected line of defence across the island from Tynemouth to Solway, which might serve at once as a bulwark against the North, and a base of operations against the Brigantes. The idea had been Agricola’s, thus showing that some at least of his relative’s overstrained eulogy is not misplaced. The line of forts which he had established was now reinstated, new ones built, and all connected by a solid rampart of turf, fronted by a deep ditch. While this was being carried out, and Hadrian was busy in the south, the field army, assisted by detachments from the Army of the Rhine, set to work to tame the Brigantes, and for a time succeeded. [Illustration: THE ROMAN WALL FROM THE MILE CASTLE BETWEEN AESICA AND BORCOVICUS.] Hadrian’s policy, as is known, was to withdraw behind definite and easily defensible frontiers, and concentrate the energies of the government upon internal development rather than aggression. The trouble in Britain was that a true frontier was hard to find. Hadrian’s chosen line corresponded roughly with the Brigantian border, but it cut athwart the British tribes. To move on to the Forth was merely to add a large tract of very wild and sparsely peopled territory to the province, with the restless Brigantes still unsubdued far in the rear. As the conditions then were, Hadrian’s policy was sound; but it may be said, in short, that the original error of occupying the island was not to be redeemed by anything short of its complete conquest, and for this task, enormously difficult and entirely unremunerative, the Roman Empire, on the verge of decline in population and resources, had not the means.