Augustus summoned to his aid whatever remained in those fierce minds of Roman prejudices; enforced the rigor of discipline by the sanction of law; and, interposing the majesty of the senate between the emperor and the army, boldly claimed their allegiance, as the first magistrate of the republic.
During a long period of two hundred and twenty years from the establishment of this artful system to the death of Commodus, the dangers inherent to a military government were, in a great measure, suspended.

The soldiers were seldom roused to that fatal sense 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: [281] 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.