Roman arms, Julius Frontinus succeeded Cerealis both in authority and in reputation: but the general who finally established the dominion of the Romans in this island, was Julius Agricola, who governed it in the reigns of Vespasian, Titus, and Domitian, and distinguished himself in that scene of action. This great commander formed a regular plan for subduing Britain, and rendering the acquisition useful to the conquerors. He carried his victorious arms northwards, defeated the Britons in every encounter, pierced into the inaccessible forests and mountains of Caledonia, reduced every state to subjection in the southern parts of the island, and chased before him all the men of fiercer and more intractable spirits, who deemed war and death itself less intolerable than servitude under the victors. He even defeated them in a decisive action, which they fought under Galgacus, their leader; and having fixed a chain of garrisons between the Friths of Clyde and Forth, he thereby cut off the ruder and more barren parts of the island, and secured the Roman province from the incursions of the barbarous inhabitants.[*] [* Tacit Ann. lib. xiv.] During these military enterprises, he neglected not the arts of peace. He introduced laws and civility among the Britons, taught them to desire and raise all the conveniences of life, reconciled them to the Roman language and manners, instructed them in letters and science, and employed every expedient to render those chains which he had forged both easy and agreeable to them.[*] [* Tacit. Agr.] The inhabitants, having experienced how unequal their own force was to resist that of the Romans, acquiesced in the dominion of their masters, and were gradually incorporated as a part of that mighty empire. This was the last durable conquest made by the Romans, and Britain, once subdued, gave no further inquietude to the victor. Caledonia alone, defended by its barren mountains, and by the contempt which the Romans entertained for it, sometimes infested the more cultivated parts of the island by the incursions of its inhabitants. The better to secure the frontiers of the empire, Adrian, who visited this island, built a rampart between the River Tyne and the Frith of Solway; Lollius Urbicus, under Antoninus Pius, erected one in the place where Agricola had formerly established his garrisons, Severus, who made an expedition into Britain, and carried his arms to the most northern extremity of it, added new fortifications to the wall of Adrian; and during the reigns of all the Roman emperors, such a profound tranquillity prevailed in Britain, that little mention is made of the affairs of that island by any historian. The only incidents which occur, are some seditions or rebellions of the Roman legions quartered there, and some usurpations of the imperial dignity by the Roman governors. The natives, disarmed, dispirited, and submissive, had lost all desire and even idea of their former liberty and independence.