The real difficulties arise in new principalities—especially those that are not entirely new, but are added to an existing state. These may be called mixed principalities, and their instability comes first from a natural and common cause: people willingly change their ruler, believing they will be better off.
This belief leads them to take up arms against their current ruler, but they soon discover, through experience, that they have made things worse. This happens because a new prince is always forced to offend those he comes to rule—through military occupation and through the many injuries that inevitably follow a conquest.
As a result, he finds himself with enemies among all those he has harmed in taking control, while being unable to fully satisfy those who helped him gain power. He cannot reward them as much as they expected, nor can he act harshly against them, since he depends on their support. No matter how strong his army may be, a ruler always needs the favor of the local population to enter and secure a new territory.
-The Prince, Machiavellie