The Italian Peninsula
A good understanding of how the Renaissance unfolded in Italy must take into account the geography and diversity within the large Italian peninsula. The Italy as we know it today is a relatively modern creation, and for much of its history the peninsula was controlled by various city-states which warred with one another and exchanged control over regions from time to time. Some of the major cities in Italy at this time included Naples in the south, Rome, Florence, Siena, Pisa, and Umbria in the central region, and Milan, Genoa, and Venice in the north.
While Rome occupied an unsurpassed role in the ancient world, the Renaissance was squarely centered around the city of Florence from the beginning. It was there that a concentration of brilliant artists and architects brought their ideas to life, although for at least some of them it only came after they had made trips to Rome to see the ruins and old works from the imperial age.
Eventually, the ideas of the Renaissance spread beyond Florence as humanist scholars throughout the peninsula became more attracted to the notion of emulating antiquity. Some of these ideas would be spread through written texts, such as the great work on architecture by Leon Battista Alberti, De Re Aedificatoria.
The center of Renaissance patronage would eventually make its way to Rome, where one of the most powerful of all art patrons lived – the pope. By the beginning of the sixteenth century, papal patronage would draw some of the greatest artists to the Eternal City, such as Raphael and Michelangelo. Rome, however, would be sacked in 1527, causing people to flee from the city. The result of this was that artists and architects who had training in Rome brought their talents and knowledge of Roman design to other cities in Italy, increasing the range of places where ideas of the Roman Renaissance would become manifest. Cities such as Venice, which became the new home of the great sixteenth century architects Sansovino, Sanmicheli, and Serlio, greatly benefited from this.
The Pursuit of Italy: A History of a Land, Its Regions, and Their Peoples, by David Gilmour