The Prince
Conquered kingdoms (Chapter 4)

In some cases, the old king of the conquered kingdom depended on his lords; 16th-century France, or in other words France as it was at the time of writing of The Prince, is given by Machiavelli as an example of such a kingdom. These are easy to enter, but difficult to hold.

When the kingdom revolves around the king, with everyone else his servant, then it is difficult to enter, but easy to hold. The solution is to eliminate the old bloodline of the prince. Machiavelli used the Persian empire of Darius III, conquered by Alexander the Great, to illustrate this point, and then noted that the Medici, if they think about it, will find this historical example similar to the "kingdom of the Turk" (Ottoman Empire) in their time – making this a potentially easier conquest to hold than France would be.
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