Florence was a republic with longstanding traditions of civic governance. Citizens voted on laws and served in official posts for set terms, with powerful families dominating the system. By 1434 the real power was in the hand of the Medici family, who controlled the city government (the Signoria) and patronized the arts. Rising from obscurity from a resolutely non-noble background, the Medici eventually became the official bankers to the papacy, acquiring vast wealth as a result. The Medici spent huge sums on the city itself, funding the creation of churches, orphanages, municipal buildings, and the completion of the great dome of the city’s cathedral, at the time the largest freestanding dome in Europe. They also patronized most of the most famous Renaissance artists (at the time as well as in the present), including Donatello, Leonardo da Vinci, and Michelangelo.
Florence benefited from a strong culture of education, with Florentines priding themselves not just on wealth, but knowledge and refinement. By the fifteenth century there were 8,000 children in both church and civic schools out of a population of 100,000. Florentines boasted that even their laborers could quote the great poet, and native of Florence, Dante Alighieri (author of The Divine Comedy). At the height of Medici, and Florentine, power in the second half of the fifteenth century, Florence was unquestionably the leading city in all of Italy in terms of art and scholarship. That central position diminished by about 1500 as foreign invasions undermined Florentine independence.
The city of Rome, however, remained firmly in papal control despite the decline in independence of the other major Italian cities, having become a major Renaissance city after the end of the Great Western Schism. The popes re-asserted their control of the Papal States in central Italy, in some cases (like those of Julius II, r. 1503 – 1513) personally taking to the battlefield to lead troops against the armies of both foreign invaders and rival Italians. The popes usually proved effective at secular rule, but their spiritual leadership was undermined by their tendency to live like kings rather than priests; the most notorious, Alexander VI (r. 1492 – 1503), sponsored his children (the infamous Borgia family) in their attempts to seize territory all across northern Italy. Thus, even when “good popes” came along occasionally, the overall pattern was that the popes did fairly little to reinforce the spiritual authority they had already lost because of the Great Western Schism
Regardless of their moral failings, the popes restored Rome to importance as a city after it had fallen to a population of fewer than 25,000 during the Babylonian Captivity. Under the so-called "Renaissance popes," the Vatican itself became the gloriously decorated spectacle that it is today. Julius II paid Michelangelo to paint the ceiling of the Sistine Chapel in Rome, and many of the other famous works of Renaissance artists stud the walls and facades of Vatican buildings. In short, popes after the end of the Great Western Schism were often much more focused on behaving like members of the popoli grossi, fighting for power and honor and patronizing great works of art and architecture, rather than worrying about the spiritual authority of the church to laypeople.