States and cities were so frequently shifting owners in the sixteenth century that the scientific politician was justified in confining his attention to the method of establishing and preserving principalities acquired by force.

When he passes to the consideration of this class, Machiavelli enters upon the real subject of his essay.

The first instance he discusses is that of a prince who has conquered a dominion which he wishes to unite as firmly as possible to his hereditary states.

The new territory may either belong to the same nationality and language as the old possession, or may not.

In the former case it will be enough to extinguish the whole line of the ancient rulers, and to take care that neither the laws nor the imposts of the province be materially altered.