So in 208 Severus himself arrived with powerful reinforcements. In 209 he advanced, and for two years pushed slowly and doggedly forward. His solution of the problem was the heroic one of subduing the whole island. The losses of the army in the two campaigns were relatively enormous--fifty thousand men, it is said. The stern old Emperor was generally ill; he suffered fearfully from gout, but he never faltered. On over the desolation of wild Caledonia, slowly, painfully, but with a grim determination more terrible than the fiercest onslaught, with Severus in his litter at its head, the devoted army wrought its way, and at last drew near to the ‘extreme end of the Isle of Britain.’[A] Severus had won his last victory, for the barbarians were cowed by the steady advance. They sued for peace, and the grim old conqueror returned to Eboracum to die. His worthless son Caracalla retroceded the conquered territory to the Picts, receiving in exchange a more or less nominal homage; but there is every reason to believe that the barbarians were daunted, and gave little trouble for many years. Severus left behind him, as a perpetual monument to his greatness, the gigantic reconstruction in stone of Hadrian’s Wall, whereof the remains survive to this day. [A] Herodian. After his departure, Britain entered upon a period of prosperity hitherto unknown. It was saved by its insular position from taking more than a passive part in the wild chaos of civil and foreign war that overwhelmed the Roman Empire in the third century, and is described by a contemporary writer as being in a very flourishing condition. The Picts were held completely in check by the fortified lines of the Wall. Perhaps, also, they were involved in warfare among themselves. At any rate, not until the end of the century did Britain again know the fear of foreign invasion. This time it was not from the North, but from oversea. The little cloud, no bigger than a man’s hand, had arisen in Germany, which was to grow until it overshadowed all the heavens, and ended by forming a new nation on what had been Celtic soil.