Florence was founded in the first century B. C. on the northern bank of the river and had its centre in the modern Piazza dell'Unità. In the early 4th century A.C. , a small group of Romans settled on the other bank, which reached the extremity of the ancient Ponte Vecchio. Merchants and travellers used to live in this area, among them a Syrian colony which distinguished itself and founded the church of Santa Felicita.
During the late Middle Ages the city "over the Arno" became bigger and more and more important: a market took place in Piazza di Santa Felicita, in the modern district of San Niccolò, where the powerful Mozzi family built a palace, which has been the biggest of the city for many years. Other noble-families built some towers, some of which may be recognized also today.
A large number of "hospitals" arose between Ponte Vecchio and Porta Romana to house pilgrims who were travelling towards Rome through the still existent Via Romana and two new bridges were built in order to develop a better connection between the two sites of the city: the Ponte alle Grazie, which was destroyed during the Second World War and rebuilt in 1957, and the Ponte a Santa Trinita, which was swept away by the floods of the Arno river.
In this way two "borghi" (villages), Borgo San Jacopo and Borgo di Piazza (today Via Guicciardini) and other settlements around the two main churches of Santo Spirito and Santa Maria del Carmine developed.
This rural and quiet area started to be seen as more wholesome compared to the northern bank characterized by relentless traffic. The Pitti, a wealthy merchant family, were among the new residents. They built the central part Palazzo Pitti, which bears the same name.
In 1550, when the Medici moved into Palazzo Pitti, the square in front of it, near Via di Maggio and other streets became very important. Here new buildings owned by families of the Medici court arose: even today, walking along Via dei Serragli, Via Santo Spirito or Via San Niccolò you can find magnificent resulting Renaissance palaces.
In 1865 many important works were made as a consequence of the transfer of the capital of Italy to Florence and led to the creation of Piazzale Michelangelo, which became the new exclusive cultural salon of Florence. This change brought about the new style of Viale Michelangelo, which takes its name from the "piazza" on the hills and consequently it became the luxurious residential area for the new middle class of Florence in the 19th, 20th centuries.
Florence was badly damaged during the 20th century by two main events: the movement of the allied troops in 1944 and the flood in 1966. Devastating floods ravaged the city in November 1966, causing inestimable damages to its buildings and works of art.
Until today the Oltrarno has preserved the most traditional atmosphere of Florence: there are some districts, almost unknown, which offer shops, cafes, restaurants and museums and a way of life which has disappeared in other districts of the city.