This is clear from the fact that after the death of Filippo Visconti, when Milan tried to regain freedom, she was unable to preserve it.'[1] Whether Machiavelli is right in referring this incapacity for self-government to the corruption of morals and religion may be questioned.

But it is certain that throughout the states of Italy, with the one exception of Venice, causes were at work inimical to republics and favorable to despotisms.
[1] _Discorsi_, i.17.The Florentine philosopher remarks in the same passage, 'Cities, once corrupt, and accustomed to the rule of a prince, can never acquire their freedom even though the prince with all his kith and kin be extirpated.

One prince is needed to extinguish another; and the city has no rest except by the creation of a new lord, unless one burgher by his goodness and his great qualities may chance to preserve its independence during his lifetime.' It will be observed in this classification of Italian tyrants that the tenure of their power was almost uniformly forcible.

They generally acquired it through the people in the first instance, and maintained it by the exercise of violence.

Rank had nothing to do with their claims.
The bastards of Popes, who like Sixtus IV.