De divina proportione
Florence was established by Lucius Cornelius Sulla in 80 BC as a settlement for his veteran soldiers and was named originally Fluentia, owing the fact that it was built between two rivers, which was later corrupted to Florentia. It was built in the style of an army camp with the main streets, the cardo and the decumanus, intersecting at the present Piazza della Repubblica. Situated at the Via Cassia, the main route between Rome and the north, and within the fertile valley of the Arno, the settlement quickly became an important commercial centre. The Emperor Diocletian is said to have made Florentia the seat of a bishopric around the beginning of the 4th century AD, but this seems improbable as Diocletian was a notable persecutor of Christians.
In the ensuing two centuries, the city experienced turbulent periods of Ostrogothic rule, during which the city was often troubled by warfare between the Ostrogoths and the Byzantines, which may have caused the population to fall to as few as 1,000 people. Peace returned under Lombard rule in the 6th century. Florence was conquered by Charlemagne in 774 and became part of the Duchy of Tuscany, with Lucca as capital. The population began to grow again and commerce prospered. In 854, Florence and Fiesole were united in one county.
Margrave Hugo chose Florence as his residency instead of Lucca at about 1000 AD. The Golden Age of Florentine art began around this time. In 1013, construction began on the Basilica di San Miniato al Monte. The exterior of the baptistery was reworked in Romanesque style between 1059, and 1128. This period also saw the eclipse of Florence’s formerly powerful rival Pisa (defeated by Genoa in 1284 and subjugated by Florence in 1406), and the exercise of power by the mercantile elite following an anti-aristocratic movement, led by Giano della Bella, that resulted in a set of laws called the Ordinances of Justice (1293).
Of a population estimated at 94,000 before the Black Death of 1348, about 25,000 are said to have been supported by the city’s wool industry: in 1345 Florence was the scene of an attempted strike by wool combers (ciompi), who in 1378 rose up in a brief revolt against oligarchic rule in the Revolt of the Ciompi. After their suppression, Florence came under the sway (1382–1434) of the Albizzi family.
In the 15th century (the so-called Quattrocento), Florence is among the largest cities in Europe, considered rich and economically successful. Life is not idyllic for all residents though, among whom there are great disparities in wealth.
Although the city is technically a democracy of sorts, the real power belongs to a couple of influential families.