Machiavelli makes a distinction between those who rise to become princes through their own abilities and those who are merely fortunate, admiring the former more and remarking that their positions are more stable. Fortune is fickle. In chapter VII, he remarks:
Those who solely by good fortune become princes from being private citizens have little trouble in rising, but have much trouble in staying at the top. They do not have any difficulties on the way up, because they fly, but they have many when they reach the top.
Machiavelli's favorite example of such a prince is Cesare Borgia, who gained his power by good fortune and quickly lost it again.
There are many references in The Prince to the capricious nature of fate and fortune—particularly in chapter XXV, which is devoted to the subject. Here, Machiavelli expands on the observation he frequently makes: that the advantages and disadvantages conferred by fortune are comparatively short-lived. Fortune may sweep a fool into a position of power or may bring down a wise and careful ruler, but neither effect will be durable. The fool will quickly lose and the wise man will gain back his power. People are also disposed to give credit to fortune for victories which are actually attributable to lack of wisdom or courage on the other side. Like a river in flood, fortune, according to Machiavelli,
shows her power where courage has not made preparations to resist her. She turns her forces where she knows that walls have not been raised to constrain her.
Throughout the text, Machiavelli yokes fortune together with some more personal and less capricious quality: wisdom, bravery, genius, or even, in chapter VIII, the capacity for wickedness. He always makes it clear that, while fortune make bring the prince in question to power, it is the other, more durable quality that keeps him there.