On the death of Commodus in the year 192, three able generals commanded the Roman troops stationed at the principal points of the boundary of the Roman empire—Pescennius Niger in Syria, Lucius Septimius Severus in Pannonia, and Clodius Albinus in Britain; and after the death of Pertinax and Didius Julianus—the short-lived emperors who had been put up and as speedily deposed by the Prætorian guards—a struggle took place between these generals for the empire. Severus was proclaimed emperor at Rome, but he found himself at once in a position of great difficulty; for both of his rivals were formidable opponents, both were in command of powerful armies devoted to them, and he could not proceed to attack the one without exposing the seat of the empire to be seized upon by the other, or remain at Rome without drawing upon himself the simultaneous attack of both. He therefore caused Albinus to be proclaimed Cæsar, had his title confirmed by the senate, and sent letters to him to invite him to share in the government, but recommended that he should make Britain the seat of his government, and devote himself to the care of that province. An example was thus for the first time set of the command of the troops in Britain being associated with the imperial dignity, which some of the succeeding commanders were not slow to imitate, and a separate interest created with reference to Britain, which tended to isolate it from the rest of the empire, and greatly affected the fortunes of both. It is unnecessary for our purpose to detail the struggle which now took place between Severus and Pescennius Niger, and resulted in the defeat and death of the latter in the year 194. Severus then led his army into Gaul to attack Albinus, who promptly met him by crossing the channel with the British army, and in the battle of Lyons which ensued, he also was defeated and slain in the year 197,[74] and Severus found himself in possession of the undivided rule of the Roman world. [Sidenote: A.D. 201. Revolt of Caledonii and Mæatæ.] It would appear that Albinus, in the course of his government, had come to terms with the barbarians or independent tribes of the north, for four years after this battle we find the natives of the Mæatæ, now for the first time mentioned, threatening hostilities against the Roman province, and the Caledonii, who are accused of not abiding by their promises, preparing to assist them. The governor, Virius Lupus, who had probably been sent as Albinus’s successor, being unable to obtain assistance from Severus in consequence of his being engaged in war elsewhere, appears to have been driven by necessity to purchase peace from the Mæatæ at a great price, a circumstance which shows the formidable character which the independent tribes of the north still bore, and the extent to which they taxed the military ability and energy of the Roman governors to protect the province from their attacks.