The Prince by Niccolo Machiavelli Chapter 19 Page 25

Prince is accepted as though he were an hereditary Sovereign.

But returning to the matter in hand, I say that whoever reflects on the above reasoning will see that either hatred or contempt was the ruin of the Emperors whom I have named; and will also understand how it happened that some taking one way and some the opposite, one only by each of these roads came to a happy, and all the rest to an unhappy end. Because for Pertinax and Alexander, they being new Princes, it was useless and hurtful to try to imitate Marcus, who was an hereditary Prince; and similarly for Caracalla, Commodus, and Maximinus it was a fatal error to imitate Severus, since they lacked the qualities that would have enabled them to tread in his footsteps.

In short, a Prince new to the Princedom cannot imitate the