reporting that no tongue of land connected Britain with the continent, that they had seen in the distance Thule (Iceland), enveloped in mists and eternal snow, and that the seas which they had traversed were of a sluggish kind, heavy under the oar, and never agitated by wind or storms. Agricola was recalled to Rome through the jealousy of the Emperor Domitian, but his wise government had appeased the passions of the Britons, and for thirty years afterwards the Roman annals contain no mention of British affairs--an evidence that peace reigned in the island. An invasion of the Caledonians brought the Emperor Hadrian to Britain (120 A.D.). Having driven them back beyond the forts which connected the mouth of the Solway on the west with that of the Tyne on the eastern coast, he caused to be raised behind this rampart an enormous wall, fortified by a wide fosse and provided with towers which received a garrison. This redoubt is still partly in existence, as is the wall of Antoninus, constructed some years later across the isthmus of the Forth, after a fresh invasion of the barbarians. {21} No rampart, however, could resist the warlike ardor of these savage populations; and the disorganization which had attacked the vast body of the Empire began to make itself felt among the legions established in Britain. The soldiers often murmured; the general, Albinus, after having refused the title of Cæsar from the hands of the Emperor Commodus, accepted it upon the offer of Septimius Severus, and, suddenly rejecting his allegiance, he was proclaimed emperor by his troops. Crossing immediately into Gaul to sustain his pretensions by force of arms, he was defeated near Revoux, and paid for his ambition by the loss of his head; but he had brought with him and had sacrificed the best of the troops in Britain, both Roman and native. The Caledonians took advantage of this opportunity to redouble their efforts, and the case became so grave that the emperor left Rome to oppose them (207 A.D.).