The Roman General Agricola had built in 78 A.D. a massive wall across the North of England, extending from sea to sea, to protect the Roman territory from the Picts and Scots, those wild dwellers in the Northern Highlands. It seems to us a frail barrier to a people accustomed to leaping the rocky wall set by nature between the North and the South; and unless it were maintained by a line of legions extending its entire length, they must have laughed at such a defence; even when duplicated later, as it was, by the Emperor Hadrian, in 120 A.D.; and still twice again, first by Emperor Antoninus, and then by Severus. For the swift transportation of troops in the defensive warfare always carried on with the Picts and Scots, magnificent roads were built, which linked the Romanized cities together in a network of splendid highways. There were more than three centuries of peace. Agriculture, commerce, and industries came into existence. "Wealth accumulated," but the Briton "decayed" beneath the weight of a splendid system, which had not benefited, but had simply crushed out of him his original vigor. Together with Roman villas, and vice, and luxury, had also come Christianity. But the Briton, if he had learned to pray, had forgotten how to fight,--and how to govern; and now the Roman Empire was perishing. She needed all her legions to keep Alaric and his Goths out of Rome. [Sidenote: Roman Legions Withdrawn, 410 A.D.] In 410 A.D. the fair cities and roads were deserted. The tramp of Roman soldiers was heard no more in the land, and the enfeebled native race were left helpless and alone to fight their battles with the Picts and Scots;--that fierce Briton offshoot which had for centuries dwelt in the fastnesses of the Highlands, and which swarmed down upon them like vultures as soon as their protectors were gone. In 446 A.D. the unhappy Britons invited their fate. Like their cousins, the Gauls, they invited the Teutons from across the sea to come to their rescue, and with result far more disastrous. When the Frank became the champion and conqueror of Gaul, he had for centuries been in conflict or in contact with Rome, and had learned much of the old Southern civilizations, and to some extent adopted their ideals. Not so the Angles and Saxons, who came pouring into Britain from Schleswig-Holstein. They were uncontaminated pagans. In scorn of Roman luxury, they set the torch to the villas, and temples and baths. They came, exterminating, not assimilating. The more complaisant Frank had taken Romanized, Latinized Gaul just as he found her, and had even speedily adopted her religion. It was for Gaul a change of rulers, but not of civilization.