By struggles such as these the contest between the Romans and the
Britons was carried on for many generations; the Romans conquering at
every trial, until, at length, the Britons learned to submit without
further resistance to their sway. In fact, there gradually came upon
the stage, during the progress of these centuries, a new power, acting
as an enemy to both the Picts and Scots; hordes of lawless barbarians,
who inhabited the mountains and morasses of Scotland and Ireland.
These terrible savages made continual irruptions into the southern
country for plunder, burning and destroying, as they retired, whatever
they could not carry away. They lived in impregnable and almost
inaccessible fastnesses, among dark glens and precipitous mountains,
and upon gloomy islands surrounded by iron-bound coasts and stormy
seas. The Roman legions made repeated attempts to hunt them out of
these retreats, but with very little success. At length a line of
fortified posts was established across the island, near where the
boundary line now lies between England and Scotland; and by guarding
this line, the Roman generals who had charge of Britain attempted to
protect the inhabitants of the southern country, who had learned at
length to submit peaceably to their sway.

One of the most memorable events which occurred during the time that
the Romans held possession of the island of Britain was the visit of
one of the emperors to this northern extremity of his dominions. The
name of this emperor was Severus. He was powerful and prosperous at
home, but his life was embittered by one great calamity, the dissolute
character and the perpetual quarrels of his sons. To remove them from
Rome, where they disgraced both themselves and their father by their
vicious lives, and the ferocious rivalry and hatred they bore to each
other, Severus planned an excursion to Britain, taking them with him,
in the hope of turning their minds into new channels of thought, and