ed the mercenary allegiance of
his followers, and left them to consult their own safety by a timely
desertion of an unsuccessful cause. It was of little moment to the
provinces, under whose name they were oppressed or governed; they were
driven by the impulsion of the present power, and as soon as that power
yielded to a superior force, they hastened to implore the clemency of
the conqueror, who, as he had an immense debt to discharge, was obliged
to sacrifice the most guilty countries to the avarice of his soldiers.
In the vast extent of the Roman empire, there were few fortified cities
capable of protecting a routed army; nor was there any person, or
family, or order of men, whose natural interest, unsupported by the
powers of government, was capable of restoring the cause of a sinking
party. [52]

[Footnote 52: Montesquieu, Considerations sur la Grandeur et la
Decadence des Romains, c. xiii.]

Yet, in the contest between Niger and Severus, a single city deserves an
honorable exception. As Byzantium was one of the greatest passages from
Europe into Asia, it had been provided with a strong garrison, and
a fleet of five hundred vessels was anchored in the harbor. [53] The
impetuosity of Severus disappointed this prudent scheme of defence; he
left to his generals the siege of Byzantium, forced the less guarded
passage of the Hellespont, and, impatient of a meaner enemy, pressed
forward to encounter his rival. Byzantium, attacked by a numerous and
increasing army, and afterwards by the whole naval power of the empire,
sustained a siege of three years, and remained faithful to the name and
memory of Niger. The citizens and soldiers (we know not from what cause)
were animated with equal fury; several of the principal officers
of Niger, who despaired of, or who disdained, a pardon, had thrown
themselves into this last refuge: the fortifications were esteemed
impregnable, and, in the defence of the place, a celebrated engineer
displayed all the mechanic powers known to the ancients. [54] Byzantium,
at length, surrendered to famine. The magistrates and soldiers were put
to the sword, the walls demolished, the privileges suppressed, and the
destined capital of the East subsisted only as an open village, subject
to the insulting jurisdiction of Perinthus. The historian Dion, who had
admired the flourishing, and lamented the desolate, state of Byzantium,
accused the revenge of Severus, for depriving the Roman people of the
stro