And if he who has become prince in any State will but reflect, how, after Rome was made an empire, far greater praise was earned those emperors who lived within the laws, and worthily, than by those who lived in the contrary way, he will see that Titus, Nerva, Trajan, Hadrian, Antoninus and Marcus had no need of prætorian cohorts, or of countless legions to guard them, but were defended by their own good lives, the good-will of their subjects, and the attachment of the senate. In like manner he will perceive in the case of Caligula, Nero, Vitellius, and ever so many more of those evil emperors, that all the armies of the east and of the west were of no avail to protect them from the enemies whom their bad and depraved lives raised up against them. And were the history of these emperors rightly studied, it would be a sufficient lesson to any prince how to distinguish the paths which lead to honour and safety from those which end in shame and insecurity. For of the twenty-six emperors from Cæsar to Maximinus, sixteen came to a violent, ten only to a natural death; and though one or two of those who died by violence may have been good princes, as Galba or Pertinax, they met their fate in consequence of that corruption which their predecessors had left behind in the army. And if among those who died a natural death, there be found some bad emperors, like Severus, it is to be ascribed to their signal good fortune and to their great abilities, advantages seldom found united in the same man. From the study of this history we may also learn how a good government is to be established; for while all the emperors who succeeded to the throne by birth, except Titus, were bad, all were good who succeeded by adoption; as in the case of the five from Nerva to Marcus. But so soon as the empire fell once more to the heirs by birth, its ruin recommenced.