The Renaissance, starting in roughly 1450, or Rebirth of obeisance to all things pagan and ancient, produced many ill effects. One was a ribald acceptance by late medieval society, of immorality, savagery, and a diminution of personal responsibility, ethics and social cohesion. We see this all over Europe – a basic reduction of all standards related to conduct, mores and social interaction.
Savonarola, the fiery, intemperate Dominican monk who rose to power in Florence during the latter part of the 15th century, was an expression of the widespread disgust with the Renaissance. Most of the lay population were not only revolted by Church, secular and political oppression and immorality; they were oftentimes the victims of the same. Unbridled corruption of the Church, of 'intellectuals', and of political life undermined public and private morality as well. The 'peasants' began to imitate their 'superiors'. Uncivilization was the result in many places, with the Medici in Florence, and the Borgia in Rome, at the forefront of this immoderate explosion in despotism and unenlightened narcissism.
Machiavelli lived during the reign of the Borgia Pope Alexander VI, easily the most debauched, lecherous, conniving, sinful, lustful, depraved holder of the Papal chair in history. His son Cesar was an outright demon, a brigand, military commander, sadist, psychopath and blood-letter of the highest order. The two of them so besmirched and ridiculed the church, that one can trace a straight line from the reign of Pope Borgia, to the 1517 proclamation by Luther against not only Church indulgences, but the general cesspit of corruption it had sunk into. Borgia is the apex of the Church's descent into madness and secular concupiscence.
Machiavelli was a man of Florence, dominated by the Medici. But it was not the Medici who were the templates for Machiavelli's bizarre theory termed 'realism', though it had precious little to do with realism, and plenty more to do with sadism, fraud, mendacity and an ethical program developed by Satan. Machiavelli was no more a 'political philosopher', than the naturalist philosopher Darwin was a scientist. Words do indeed have meaning. Machiavelli was first and only, an admirer of the Borgia, a ruthless gangster family from Spain which usurped in the guise of Borgia the elder, the Papacy and political-military control of vast swathes of Italy. Alexander the VI or Borgia the elder, was no more a Pope, than Richard Dawkins is an apostle of reason or science.
From Mallett, and his history named 'Borgias': “....Later in July, in one of the lightning military moves for which he was famous, Caesar [Borgia, son of the Pope] swept into the duchy of Urbino and conquered it almost without firing a shot. It was soon after this that Niccolo Machiavelli of Florence joined him, becoming his great admirer and making him the generally recognized model for 'the prince' in famous and evil book on politics...” 
Machiavelli's evil admonition that all princes, real or aspiring, and all claimants to power or influence real or aspiring, must ape and mimic a fantastically insane example such as Caesar Borgia, is an expression of insanity, not political philosophy. There is nothing intelligent, elucidating, attractive or even benign in such an assertion, nor in such a man as Caesar Borgia. Yet 'historians' credit Machiavelli with 'insights', with his loathing of humans and of the world at large, somehow making 'political philosophy', more 'scientific' and real. All Machiavelli did was to enshrine as divine, the savage barbarism of Caesar Borgia. What is the 'rebirth' of knowledge in such a claim ?
Machiavelli was like many others – Lenin, Bonaparte, Rousseau, Hume, Marx, Freud, Darwin and too many others to list – a product of his times, with his own peculiar and quite deformed personality, finding succor and 'proof', in his philosophy. As with the Phd in gender studies justifying their 10 years of 'research', or their own sexual deviancy's, so one can see the deformed, twisted, sick, pathological ill Machiavelli resplendently reflected through his hero, the savage and barbarian Borgia, and his ode to immorality, 'the prince'. Machiavelli was not a scientist, not a philosopher, not a man who was reborn or enlightened. He was just another product of evil and just another example of a mental illness parading as the rational.