The Prince by Niccolo Machiavelli Chapter 12 Page 5

And we see from experience that both Princes and Republics when they depend on their own arms have the greatest success, whereas from employing mercenaries nothing but loss results. Moreover, a Republic trusting to her own forces, is with greater difficulty than one which relies on foreign arms brought to yield obedience to a single citizen. Rome and Sparta remained for ages armed and free. The Swiss are at once the best armed and the freest people in the world.

Of mercenary arms in ancient times we have an example in the Carthaginians, who at the close of their first war with Rome, were well-nigh ruined by their hired troops, although these were commanded by Carthaginian citizens. So too, when, on the death of Epaminondas, the Thebans made Philip of Macedon captain of their army, after gaining a victory for them, he