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 firth 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 more
northern extremity of it, added new fortifications to the walls 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.

But the period was now come when that enormous fabric of the Roman
empire, which had diffused slavery and oppression, together with peace
and civility, over so considerable a part of the globe, was
approaching towards it final dissolution. Italy and the centre of the
empire, removed, during so many ages, from all concern in the wars,
had entirely lost the military spirit, and were peopled by an
enervated race, equally disposed to submit to a foreign yoke, or to
the tyranny of their own rulers. The emperors found themselves
obliged to recruit their legions from the frontier provinces, where
the genius of war, though languishing, was not totally extinct; and
these mercenary forces, careless of laws, and civil institutions,
established a military government, no less dangerous to the sovereign
than to the people. The further progress of the same disorders