During the remainder of Domitian’s reign, and that of Hadrian his successor, North Britain appears to have enjoyed tranquillity; an inference which may be fairly drawn from the silence of the Roman historians. Yet as Hadrian in the year 121 built a wall between the Solway and the Tyne, some writers have supposed that the Romans had been driven by the Caledonians out of North Britain, in the reign of that Emperor. But if such was the case, how did Lollius Urbicus, the Roman general, about nineteen years after Hadrian’s wall was erected, penetrate without opposition to Agricola’s forts between the Clyde and the Forth? May we not rather suppose that the wall of Hadrian was built for the purpose of preventing incursions into the south by the tribes which inhabited the country between that wall and the Friths? But, be this as it may, little is known of the history of North Britain from the time of Agricola’s recall till the year 138, when Antoninus Pius assumed the imperial purple. That good and sagacious emperor was distinguished by the care which he took in selecting the fittest officers for the government of the Roman provinces; and his choice, for that of Britain, fell on Lollius Urbicus. The positive information concerning the transactions of this general in North Britain is as meagre as could possibly be, the only clearly ascertained fact in connection with his command being that he built a wall between the Forth and Clyde, very nearly on a line with the forts established by Agricola. “The meagreness of all ancient record,” says Burton,[13] “of the achievements of Lollius Urbicus is worthy of emphatic mention and recollection, because his name has got into the ordinary abridged histories which speak of it, and of ‘his campaign in the north’ as well-known events, of which people naturally expect fuller information elsewhere. The usual sources for reference regarding him will however be found utterly dumb.” The story commonly given is that he proceeded north as far as the Moray Frith, throwing the extensive country between Forth and Clyde and the Moray Frith into the form of a regular Roman province, which, on the worthless authority of the pseudo-Richard, was named Vespasiana. All this may have been the case, and the remains[14] of Roman stations found throughout the wide tract just mentioned give some plausibility to the conjecture; but there is only the most slender grounds for connecting them with any northern expedition of Lollius Urbicus. At all events we may very safely conclude, from the general tone of the records which remain of his and of subsequent expeditions, as well as from the fact that they found it necessary to divide the Lowlands from the Highlands by a fortified wall, that the Romans considered the Caledonians of their time very troublesome, and found it exceedingly difficult if not impossible to bring them under their otherwise universal yoke. [Illustration: Map and Profile of Antonine’s Wall.]