In the second part of The Prince, Machiavelli turns his attention to military matters, describing the various types of troops available to a prince and how he should defend his principality and prepare for war. Good laws and good arms are what Machiavelli describes as the chief foundations of all states, adding that one cannot exist without the other. In regard to the arms with which a prince can defend his state, he explains that there are four varieties: one’s own troops, meaning native soldiers; mercenaries, meaning hired soldiers; auxiliaries, meaning troops supplied by an outsider; and mixed troops, meaning native troops supplemented by either mercenary or auxiliary troops. Regarding mercenaries, Machiavelli states matter-of-factly that they are useless and dangerous to a prince because “they have no other attraction or reason for keeping the field than a trifle of stipend, which is not sufficient to make them willing to die for you” (45).

The chief issue that Machiavelli has with the use of mercenary troops is that those who are not talented and courageous will lead the prince to ruin from their failure in battle, but those who are talented and courageous “always aspire to their own greatness, either by oppressing you, who are their master, or others contrary to your intentions” (46).