The most memorable, or at least iconic, effects of the Renaissance were artistic (considered in the next chapter). To understand why the Renaissance brought about such a remarkable explosion of art, it is crucial to grasp the nature of patronage. In patronage, a member of the popoli grossi would pay an artist in advance for a work of art. That work of art would be displayed publicly - most obviously in the case of architecture with the beautiful churches, orphanages, and municipal buildings that spread across Italy during the Renaissance. In turn, that art would attract political power and influence to the person or family who had paid for it because of the honor associated with funding the best artists and being associated with their work. While there was plenty of bloodshed between powerful Renaissance families, their political competition as often took the form of an ongoing battle over who could commission the best art and then "give" that art to their home city, rather than actual fighting in the streets.
Perhaps the most spectacular example of patronage in action was when Cosimo de Medici, then the leader of the Medici family and its vast banking empire, threw a city-wide party called the Council of Florence in 1439. The Council featured public lectures on Greek philosophy, displays of art, and a huge church council that brought together representatives of both the western Latin Church and the Eastern Orthodox church in a (doomed) attempt to heal the schism that divided Christianity. The Catholic hierarchy also used the occasion to establish the canonical and in a sense “final” version of the Christian Bible itself (in question were which books ought to be included in the Old Testament). The entire affair was paid by Cosimo out of his personal fortune - he even paid for the travel expenses of visiting dignitaries from places as far away as India and Ethiopia. The Council clinched the Medici as the family of Florence for the next generation, with Cosimo being described by a contemporary as a “king in all but name.”
Art and learning benefited enormously from the wealth of northern Italy precisely because the wealthy and powerful of northern Italy competed to pay for the best art and the most innovative scholarship - without that form of cultural and political competition, it is doubtful that many of the masterpieces of Renaissance art would have ever been created.
Image Citations (Creative Commons):
Cosimo de Medici - Public Domain
Printing Press - Graferocommons