se of their
own strength, and of the weakness of the civil authority, which was,
before and afterwards, productive of such dreadful calamities. Caligula
and Domitian were assassinated in their palace by their own domestics:
* the convulsions which agitated Rome on the death of the former, were
confined to the walls of the city. But Nero involved the whole empire in
his ruin. In the space of eighteen months, four princes perished by
the sword; and the Roman world was shaken by the fury of the contending
armies. Excepting only this short, though violent eruption of military
license, the two centuries from Augustus to Commodus passed away
unstained with civil blood, and undisturbed by revolutions. The emperor
was elected by the authority of the senate, and the consent of the
soldiers. The legions respected their oath of fidelity; and it requires
a minute inspection of the Roman annals to discover three inconsiderable
rebellions, which were all suppressed in a few months, and without even
the hazard of a battle.

In elective monarchies, the vacancy of the throne is a moment big with
danger and mischief. The Roman emperors, desirous to spare the legions
that interval of suspense, and the temptation of an irregular choice,
invested their designed successor with so large a share of present
power, as should enable him, after their decease, to assume the
remainder, without suffering the empire to perceive the change of
masters. Thus Augustus, after all his fairer prospects had been snatched
from him by untimely deaths, rested his last hopes on Tiberius, obtained
for his adopted son the censorial and tribunitian powers, and dictated a
law, by which the future prince was invested with an authority equal to
his own, over the provinces and the armies. Thus Vespasian subdued
the generous mind of his eldest son. Titus was adored by the eastern
legions, which, under his command, had recently achieved the conquest
of Judaea. His power was dreaded, and, as his virtues were clouded by the
intemperance of youth, his designs were suspected. Instead of listening
to such unworthy suspicions, the prudent monarch associated Titus to the
full powers of the Imperial dignity; and the grateful son ever approved
himself the humble and faithful minister of so indulgent a father.

The good sense of Vespasian engaged him indeed to embrace every measure
that might confirm his recent and precarious elevation. The military
oath, and the fidelity of the t