We don't know when the original town was built, but there was an Italic settlement, then taken over by the Etruscans.
Uder Silla became a Roman town with the augural name of Florentia. The city had no importance during the Roman Empire and Barbarian rule. It reached autonomy around 1115, when it succeeded in proclaiming itself a free Commune and established supremacy over the nearby towns. The wealthy noble class had the upper hand in ruling the Comune. The nobility was divided into two factions: the Amidei and Uberti and the Buondelmonti and Donati, under the names of Ghibellines and Guelphs they fought for nearly a century. After the victory of Monteaperti (1260), the Ghibellines returned (who had been thrown out of the city ten years earlier) with farinata degli Uberti at their head, but after the fall of the Swabians the Guelphs triumphed once more (1276).
Towards the end of thirteenth century the population, with the publication of the Ordinamenti di Giustizia by Giano della Bella, rebelled against the return of the feudal lords; these orders entrused the government to the Trade Guilds (nobles and rich merchants). In 1300 the Guelphs split into Bianchi and Neri, led by Cerchi and the Donati. The priors (including Dante Alighieri) exiled the leaders of the two factions, but then the Neri (Blacks) exiled the Bianchi (Whites) and then Dante himself (1302). In 1342 Gautier of Brienne, Duke of Athens obtained the signory of Florence for life, but in 1343 the Florentines threw him out of the city. In the 1375 Florence entered into war with Pope Gregory XI which led to the Ciompi revolt (1378) for a economic and political crisis, and the people under the control of Guilds represented itself. Then the upper middle class abolished the New Guilds (1382) . Florence came under the rule of the richest families (Albizi, Capponi, Uzzano), and was divided into two opposing groups, an aristocratic faction and a popular faction. The rich family of the Medici with Cosimo the Elder, having defeated the Albizi, managed to gain control of the city in the 1434 . After Cosimo (1434-64) the supremacy of the Medicis continued with Piero il Gottoso (1464-69), and with his son Lorenzo, who was known as the Magnificent ( 1449-92). He managed to defeat the Pazzi conspiracy 1478) and consolidate his own power; by making an alliance with Naples and Milan. When Lorenzo died at the age of forty, his son Piero was not able to continue his father's work. Charles VIII occupied Florence in 1494. The Florentines, encouraged by the preaching of the Dominican friar Girolamo Savonarola, managed to throw him out and proclaimed the Republic (1494-1512). The vigour of Savonarol.a's religious reform was not well tolerated by Pope Alexander VI Borgia. Savonarola was hanged in Piazza della Signoria on 23rd May 1498. The Medici, having returned to Florence, strengthened their power by placing two members of their family on the pontificaI throne (Leo X and Clement VII). The Peace of Barcellona between the Pope and the Emperor (1529) marked the end of the Second Republic. The Medici family, with Alexander who had earned the title of Duke (1532) and Cosimo I with the title of Grand-Duke (1569) , officially asserted its power and with the conquest of Siena (1555) expanded the frontiers of its State over which the family ruled uncontested until 1737 when, with Gian Gastone, the last of the Medici, the family became extinct and the Grand Duchy passed to Francis Stephan, Duke of Lorraine, and husband of Maria Teresa of Hapsburg, then Empress of Austria. Tuscany therefore remained closely tied to the house of Hapsburg-Lorraine until the death of Francis Stephan in 1785 and then with his second son Peter Leopold as Grand Duke. Tuscany remained under the rule of the Hapsburg-Lorraine family up to 1860 when with a plebiscite it became part of the reign of Victor Emmannel II. With the unification of Italy, Florence became capital of the new Kingdom (1865-1871).
During the second world war Florence was the scene of fighting between the partisans and German troops and suffered heavy damage especially in the oldest parts of the city on both sides of Ponte Vecchio, the only bridge over the Arno spared by the Germans.