Machiavelli turns from how principalities are acquired and held to how they are defended. Good laws require good arms, and a prince's arms are either his own, mercenary, auxiliary, or mixed. Mercenaries and auxiliaries are useless and dangerous: disunited, ambitious, undisciplined, brave among friends and cowardly before enemies. In peace they rob you; in war the enemy defeats you because they will not die for a stipend.
Italy's ruin proves the point. For years her princes rested on mercenaries who looked formidable until Charles VIII seized the peninsula with chalk in hand. Machiavelli says the real sin was princely reliance on hired arms, and princes paid the penalty.
Mercenary captains create a double trap. If they are able, they aspire to their own greatness and may oppress you or pursue goals against your interest. If they are unable, you are ruined in the ordinary way. Machiavelli answers critics by insisting that princes should command in person and republics should send citizens, recalling failures and binding successes by law. Rome, Sparta, and the Swiss stayed armed and free.
History fills the chapter with warnings: Carthage oppressed by mercenaries; Philip of Macedon taking Theban liberty; Francesco Sforza beating the Venetians at Caravaggio then crushing Milan, his employers; Pagolo Vitelli showing Florence that a victorious captain becomes master whether you obey or resist. Venice prospered at sea with its own men, then on land hired Carmignuola, murdered him when he grew too strong and lukewarm, and later lost at Vaila in one battle what eight hundred years had built.
Machiavelli traces Italy's mercenary habit to Church and republics unaccustomed to arms after the empire's fall. From Alberigo da Conio's school came captains like Braccio and Sforza who debased infantry, inflated cavalry, and wrote rules to avoid fatigue and danger until Charles, Louis, Ferdinand, and the Swiss reduced Italy to slavery and contempt.
Coming Up in Chapter 13
In the next chapter, Machiavelli turns to another crucial aspect of power and leadership Machiavelli turns from mercenaries to auxiliaries, the allied troops a prince calls in for aid. They may be good in themselves, but for the prince who borrows them they are always disadvantageous: if you lose, you are undone; if you win, you are their captive..
