What three factors contributed to the start of the Renaissance in Italy?

The three main factors leading to the start of the Italian Renaissance are: 1) Government; 2) Banking; and 3) Intellectual Development.
The Proto-Renaissance period between 1200 and 1400 A.D. marks the transition from Medieval Europe and the power of the Catholic Church as the main political authority in Italy. Depicted in Ambrogio Lorenzetti’s 14th century fine art painting, “Effects of Good Government in the City and in the Country” exhibited in the Sala della Pace, Palazzo Pubblico in Siena, the transition to the Italian Renaissance lasting to the 17th century, restored civis (civic life) to polity after ten centuries of Medieval life.
Government
Lorenzetti’s work reflects the first factor creating the conditions for the start of the Italian Renaissance, illustrating the social and political scenario that culminated from centuries of warring between the city-states of Ferrara, Florence, Genoa, Mantua, Milan, Pisa, Siena, Verona, Venice, and finally, the Vatican. By the 15th century, the Duchy of Milan, Florence and Venice had annexed smaller communities nearby to consolidate power, emerging as the most powerful political and military forces of High Medieval Northern Italy and enjoining in a final successful battle for separation from the Papacy.
Banking
The 1454 “Peace of Lodi” truce between Florence, Milan and the international port city of Venice opened the door to a future of secular government, and with it, the expansion of mercantile trade. The Medici Bank, a financial institution established by the Republican Medici family in the 15th century presents the second factor in the historical developments promoting the Italian Renaissance. Creating a vital instrument for deposit and withdrawal of an extracted exchange value, the banking system enabled Italian merchants to no longer be reliant on the bartering of goods and services for exchange, resulting in individual prosperity, and eventually a robust economy throughout Europe.
Intellectual Development
Under the control of founder and politician, Giovanni Medici, and later son, Cosimo di Giovanni de’ Medici, the Medici Bank was also largely responsible for the third factor of the Italian Renaissance: the commission of many great artistic and scientific works. The Medici and other wealthy patrons offered artists, philosophers, and scientists, such as Leonardo da Vinci, Masaccio, and Donatello, an opportunity to advance their knowledge and technical skill beyond the Medieval patronage of the Vatican.
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https://www.history.com/topics/renaissance/renaissance-art

https://www.historytoday.com/archive/rise-and-fall-medici-bank