THE ANCIENT CITY OF FLORENCE.

Florence was set at the confluence of two streams, the Arno and the Mugnone, where the oldest populations had previously been located.
Rectangular in plan, it was enclosed in a wall about 1,800 meters long. The build-up area, like all the cities founded by Romans, was characterized by straight roads which crossed at right angles. The two main roads led to 4 towered gates and converged on a central square, where the Temple dedicated to the Capitoline Triad (Jupiter, Juno, and Minerva) were later to rise.
Archaeological finds, many of which came to light during the course of works which "gave new life," to the old city center, have been made it possible to locate and identify the remains of varios important public works such as the Capitoline Baths, the Baths of Capaccio, the sewage system, the pavement of the streets and the Temple of Isis, in Plaza San Firenze. At that time the Arno River was outside the walls, with a river port that constituted an important infrastructure for the city, for in Roman times the River was navigable from its mouth up to its confluence with the Affrico, upstream from Florence, and the first bridge in Florentine history was built in all likelihood somewhat upstream from today's Ponte Vecchio, around the 1st century BC.
Florence developed rapidly thanks to its favorable position and the role it played in the ambit of the territorial organization in the region and it soon passed Arezzo as the leading center in Northern Etruria.
Economic power was the driving force behind the urban growth of the young colony. Commercial activity and trade thrived thanks to the fact that important communication routes, land and water, intersected at Florence and offer an explanation for the presence of those oriental merchants, probably on their way from Pisa, who first introduced the cult of Isis.
The earliest indications of Christian religion are bound to the cults of the deacon Lorenzo and the Palestinian saint, Felicita and so the 1st Florentine churches were built. However, they do not seem to have had a bishop prior to the late 3rd century.
The Barbarian invasions seriously impaired the importance of Florence. In 405, the city managed to halt the hordes of Rada'gaisus, but later it could not avoid being involved in the disastrous Gotho-Byzantine war. In 541-44 new city walls were built utilizing the structures of various large Roman buildings. The wall was trapezoidal and its modest size testifies to the decline of the city, greatly depopulated; there may have been less than a thousand inhabitants. Around the end of the 6th century when the Lombards conquered Northern and Central Italy, Florence also fell under their dominion. This was the beginning of the darkest period in the city's history. Cut off from the major routes, the main reason for its existence suddenly vanished. For their North-South communications, the Lombards abandoned the central Bologna-Pistla-Florence route as being too exposed to the incursions of the Byzantines  who still held control of the Eastern part of Italy and Lucca was chosen as capital of the duchy of Tuscany as it lay along the road they used for internal communications. After Queen Theodolinda was converted to the church of Rome, a number of religious buildings were founded in the city, not of course in its present form and size and its foundations are still visible in the "subterranean"of the church.
In the 8th century, the Carolingian period, a feudal system was installed and Florence became a county of the Holy Roman Empire. In the 9th century various facts testify a revival of the city. A public ecclesiastic school was set up and the bridge over the Arno River, which had been destroyed, seems to have been rebuild. At the turn of the century new city-walls were built for fear of the Hungarian invasions. Towards the end of the 10th century, Countess Willa, widow of the Marquis of Tuscany, who owned an entire district within the city-walls, founded and endowed a Benedictine abbey in memory of her husband. Countess Willa's son Hugo, greatly contributed to the development of Florence thanks to his decision to leave Lucca. His choice of the city on the banks of the Arno as his dwelling place reinforced its administrative character.
In the middle of the 11th century the position of Florence in Tuscany became even more important because Lucca was no longer the seat of the Marquisate and because of the city's decisive participation in the movement for the reform of the church. In 1055 Florence even played host to a council, under Pope Victor II with the presence of Henry III and the participation of 120 bishops. Many old structures were rebuilt during the 2nd half of the 11th century. On November 6, 1059, Bishop Gerard, who had become pope under the name of Nicholas II, re-consecrated the ancient baptismal church of the city which had been rebuilt in more imposing form, much like what it is today. In 1115 the Florentine populace to all effects already constitute a Commune. The first mention of an officially constituted Commune dates to 1138, when at a meeting of the Tuscan cities it was decided to constitute a League, for fear that Henry the Proud who had oppressed them as imperial legate might be elected emperor.
At that time the community was made up of religious and secular representatives, with 3 dominant social groups: -nobles, grouped into consorterie, -merchants, and the horse soldiers, the backbone of the army. Although the nobles held most of the power in the 12th century, it was mainly the merchants who were responsible for the growth of the city. Extensive trade and its inseparable companion, credit, were the basis for the economic and demographic expansion of the city. It underwent a temporary halt when Frederick Barbarossa advanced South into Italy.
In 1172 the Commune decided to enlarge the city walls and incorporate newest districts. The perimeter of the new city walls, raised in barely 2 years, from 1173 to 1175, was twice that of the "old circle" and enclosed an area that was 3 times as great. As a result the Arno River became an infrastructure within the city, as a communication route, a source of energy and a water supply for industries.
In the 12th century the skyline of the city was punctuated by numerous towers that served for military purposes and gave birth to the phenomenon of the "Tower Societies" associations which reunited the owners of various towers enabling them to control a portion of the city. Later the towers were used as houses. A considerable amount of small and large churches also sprang up as the size of the city increased. In 2 centuries the number of churches in Florence was tripled.
In 1182 the merchants, who had begun to organize in corporate association, on the example of the Society of Knights, multiplied and spread well beyond the limits of their region. Florence thus became an international economic center, with its operators in the principal fairs of the West. The development of the economy went on at such a rate that in a few years the associations multiplied among the other categories of tradesmen and artisans, whose numbers increased considerably. Also accelerated immigration from the countryside, lay at the basis of this economic expansion. This was why Oltr'Arno, on which the populous Southern regions converged, increased enormously and a new bridge in wood on stone piers was constructed in 1128 and in 1237 a third bridge was built upstream. This bridge, completely in stone, was set across the widest point of the Arno and was eventually called Ponte alle Grazie, after the small church which was built on one of its piers in the middle of the 14th century.
During the 14th century, internal strife and wars were aggravated by famine and epidemics, particularly the deadly Black Plague of 1348, which aggravated a situation that was already precarious. Before the Plague a disastrous flood of 1333 swept away all the bridges over the Arno River except the Rubaconte. The 14th century was therefore a century of political and economic crisis again.