Whoever conquers a free town and does not demolish it commits a great error and may expect to be ruined himself.

This maxim comes from Machiavelli’s discussion of how a prince should hold newly acquired territories, especially republics accustomed to self-government. Writing in the early 16th century amid the Italian Wars and the volatile politics of city-states, Machiavelli drew lessons from Roman history and contemporary examples of conquered cities that repeatedly rebelled. In The Prince he argues that “free towns” (former republics) retain strong civic memory and institutions; if a conqueror tries to rule them without either destroying them, residing there, or allowing them to keep their laws under tight control, the conqueror invites constant insurrection and eventual downfall.

Machiavelli’s point is not moral approval of destruction but a hard-edged claim about political psychology and institutional inertia. A city that has lived free will not easily accept a new master; its citizens remember former liberties and have networks capable of organizing resistance. Therefore, half-measures—occupying the city while leaving its civic structure and identity intact—create a standing threat to the conqueror. The line encapsulates Machiavelli’s broader theme: stability often depends on decisive, sometimes brutal choices, and rulers are “ruined” when they ignore how power is sustained by controlling institutions, loyalties, and collective memory.