he Highland clans
that brought Roman Britain to its doom. The Saxons, as tradition tells
us, would never have been invited into the land but for the ravages
of these Picts; and, in sober history, it may well be doubted whether
they could ever have effected a permanent settlement here had not the
Britons, in defending our shores, been constantly exposed to Pictish
attacks from the rear.

D. 2.--Thus our earliest notice of Britain in this period tells us
that Hadrian (A.D. 120), our first Imperial visitor since Claudius
(A.D. 44), found it needful (after a revolt which cost many lives,
and involved, as it seems, the final destruction of the unlucky Ninth
Legion, which had already fared so badly in Boadicea's rebellion[256])
to supplement Agricola's rampart, between Forth and Clyde, with
another from sea to sea, between Tynemouth and Solway, "dividing the
Romans from the barbarians."[257] This does not mean that the district
thus isolated was definitely abandoned,[258] but that its inhabitants
were so imperfectly Romanized that the temptation to raid the more
civilized lands to the south had better be obviated. The Wall of
Hadrian marked the real limit of Roman Britain: beyond it was a
"march," sometimes strongly, more often feebly, garrisoned, but never
effectually occupied, much less civilized. The inhabitants, indeed,
seem to have rapidly lost what civilization they had. Dion Cassius
describes them, in the next generation, as far below the Caledonians
who opposed Agricola, a mere horde of squalid and ferocious
cannibals,[259] going into battle stark-naked (like their descendants
the Galwegians a thousand years later),[260] having neither chief nor
law, fields nor houses. The name Attacotti, by which they came finally
to be known, probably means _Tributary_, and describes their nominal
status towards Rome.

D. 3.--How hopeless the task of effectually incorporating these
barbarians within the Empire appeared to Hadrian is shown by the
extraordinary massiveness of the Wall which he built[261] to keep them
out from the civilized Provinces[262] to the southwards. "Uniting the
estuaries of Tyne and Solway it chose the strongest line of defence
available. Availing itself of a series of bold heights, which slope
steadily to the south, but are craggy precipices to the north, as if
designed by Nature for this very purpose, it pursued its mighty course
across the isthmus with a pertinacious, undeviating determination
which make