Towards the close of the third century the succession of usurpers who sprang up everywhere in the outlying portions of the Empire contained six who came from Britain. What effect these movements had upon the security of South London we have no means of learning. The history, however, of Carausius and his successor Allectus affords material for reflection. The former, who was of Belgian origin, rose to be the Count of the Saxon Shore--in other words, Admiral of the Roman Fleet. In this capacity he kept the seas free from pirates; enriched himself, became famous for his courage and his generosity; usurped the title of Cæsar, fought with and defeated the fleets of Maximian, and reigned in Britain for seven years. His headquarters were Boulogne and Southampton; near the latter place--at Bittern--is still seen the quay at which his ships were moored. His rule, of which we know little, was certainly strong and firm. Coins exist in great numbers of Carausius. They represent his arrival: 'Expectate, veni'--'Come, thou long-expected!' Then his triumph: 'Shout IO ten times.' He held gladiatorial sports at London; he appointed a British senate. Then came the time when he must fight or die. Like the King of the Grove, the Usurper held his throne on that condition. Carausius, for some unknown reason, would not fight when the chance was offered--therefore he died. Another King of the Grove, Allectus by name, one of his officers, killed him and reigned in his stead. Then he, too, had to fight for crown and life. He accepted the challenge; he awaited with an army of Franks and Britons the arrival of the Roman forces sent to quell him: he awaited them in London. When the enemy drew near, he led out his men across the Bridge, and gave battle to the Roman general, Asclepiodotus, on the wild heath south of London, immediately beyond the rising ground--we now call the place Clapham Common--and there he fell bravely fighting. He had enjoyed the purple for three years. Perhaps, when he crossed the Bridge, conscious that he was going to meet his fate--either to continue an Emperor for another spell or to die--he reflected that for such a splendid three years' run it was worth while to risk, and even to lose, his life at the end.