prosperously and with great glory, because he wisely set bounds to
his ambition, and contented himself with the possession of a great
country, detached from the rest of the world, and therefore easily
defended. Had he lived long enough, and pursued this plan with
consistency, Britain, in all probability, might then have become, and
might have afterwards been, an independent and powerful kingdom,
instructed in the Roman arts, and freed from their dominion. But the
same distemper of the state which had raised Carausius to power did not
suffer him long to enjoy it. The Roman soldiery at that time was wholly
destitute of military principle. That religious regard to their oath,
the great bond of ancient discipline, had been long worn out; and the
want of it was not supplied by that punctilio of honor and loyalty which
is the support of modern armies. Carausius was assassinated, and
succeeded in his kingdom by Allectus, the captain of his guards. But the
murderer, who did not possess abilities to support the power he had
acquired by his crimes, was in a short time defeated, and in his turn
put to death, by Constantius Chlorus. In about three years from the
death of Carausius, Britain, after a short experiment of independency,
was again united to the body of the Empire.

[Sidenote: A.D. 304]

Constantius, after he came to the purple, chose this island for his
residence. Many authors affirm that his wife Helena was a Briton. It is
more certain that his son Constantine the Great was born here, and
enabled to succeed his father principally by the helps which he derived
from Britain.

[Sidenote: A.D. 306.]

Under the reign of this great prince there was an almost total
revolution in the internal policy of the Empire. This was the third
remarkable change in the Roman government since the dissolution of the
Commonwealth. The first was that by which Antoninus had taken away the
distinctions of the _municipium_, province, and colony, communicating to
every part of the Empire those privileges which had formerly
distinguished a citizen of Rome. Thus the whole government was cast into
a more uniform and simple frame, and every mark of conquest was finally
effaced. The second alteration was the division of the Empire by
Diocletian. The third was the change made in the great offices of the
state, and the revolution in religion, under Constantine.

The _praefecti praetorio_, who, like the commanders of the janizaries of
the Porte, by