It has been the general practice of princes, for the purpose of holding their states securely, to build fortresses to serve as a curb and check upon those who might make an attempt against the government, and at the same time to aford the prince a secure place of refuge against the frst attack. [...] Fortresses then are useful or not, according to circumstances; and whilst in one way they are advantageous, they may in another prove injurious to a prince. Te question may therefore be stated thus. A prince who fears his own people more than he does foreigners should build fortresses; but he who has more cause to fear strangers than his own people should do without them.