In this great war, which ended in the conquest of Gaul, Cæsar’s expeditions to Britain were mere episodes which have been greatly exaggerated in the traditional histories of our schools. They were summer raids, like his dash across the Rhine, intended for a warning to the barbarians of the hinterland; for it seems that communication to and fro across the channel was continuous. It is probable enough that the persuasions of the Roman traders who swarmed after the eagles across Gaul had their influence also. Undoubtedly the Romans of this generation were keenly alive to commercial openings, and always on the search for mines, real or imaginary. Further, we cannot deny that Cæsar in all his undertakings had one eye upon his political position in Rome itself, and the “conquest of Britain,” that almost legendary corner of the earth, concealed in boreal mists and embosomed in the ever-flowing Ocean river, would be a sensational achievement calculated to outshine the Oriental triumphs of Pompeius. One cannot but place among the extravagances of hero-worship Mommsen’s belief that Cæsar had a prophetic insight into the true nature of the “German Peril” for Rome. When Cæsar took over the Gallic province there was no tremendous German menace. There had always been occasional irruptions of the barbarians from across the Rhine, and a steady German penetration of the Netherlands. Cæsar did not lay down any intelligible frontier policy: that was one of the achievements of Augustus. Both in Gaul and Britain it was simply a forward movement by a general of bold and untiring resolution, backed by an invincible army. The two trips to Britain, like those across the Rhine, were reconnaissances only, and the conquest of the island was one of the legacies which Cæsar intended to reserve for the future. His successor very wisely declined it. There was little immediate profit there, and the Gallic conquests had glutted the Roman market with slaves.