The signs of recovery that Florence showed in the ninth and tenth centuries were consolidated at the beginning of the new millennium. There is a lack of archaeological data and written sources documenting the city’s economic and demographic situation with certainty, but some clues point to a general tendency to expansion, which was echoed in the urban layout.
In 1040, the river port near the church of San Remigio is documented for the first time and must have occupied a bend in the river that has now disappeared but is still visible in the radial layout of the buildings between Via dei Neri and Via della Mosca. A series of hamlets outside the walls also began to appear, starting with the one between the southern gate and the Arno. In this area, many houses and blacksmiths’ workshops are already mentioned in a document from 1038, and a few decades later the church of the Santissimi Apostoli and the homonymous village are mentioned for the first time. This area was defended to the east by a wall that extended the old city wall as far as the Arno, where a sort of small fortified citadel, the Castello d’Altafronte, was located.
As in ancient times, the expansion of the city took place along the main roads outside the walls. Between 1090 and 1138, we have evidence of the existence of a village outside the San Piero gate, located on the eastern side of the walls; of the village of Balla, built along the road to Fiesole; of the village of San Remigio, between the town and the remains of the Roman amphitheatre. Around 1175, the church of Santa Maria Soprarno was also built, not far from the southern end of the bridge, testifying also to the progressive populating of the area of the Oltrarno – on the far side of the River Arno.
The demographic increase seems to have been accompanied by a more complex spatial and functional arrangement of the town layout. In 1076, for instance, the market of Porta Santa Maria is mentioned for the first time, later simply called Mercato Nuovo (New Market). Evidently at least a part of the trade moved from the older market area corresponding to the Roman forum, which began to be called Mercato Vecchio (Old Market). Between the eleventh and twelfth centuries, the number of religious buildings constructed in and around the city also increased. Ecclesiastical institutions promoted and organised urban development by subdividing the land they owned, the fruit of donations from the faithful, to sell or rent for the purpose of building houses. The plots often took on an elongated rectangular shape, 4 to 6 metres wide and about 15 to 20 metres deep, on which simple houses were built adjacent to each other: terraced and usually on two floors. This type of dwelling, complemented at the back of the lot by a vacant space used as a vegetable garden or workplace, formed the basis of the building fabric of many areas built from this period onwards.
At the beginning of the twelfth century, allotments even within the city walls already seem to have been numerous. One must therefore assume that the urban fabric had become dense, and that the numerous vacant spaces of the Carolingian period had been largely filled. In addition, during the twelfth century, towers belonging to groups of aristocrats are mentioned with increasing frequency. Ownership and use of these for representative and military purposes was regulated by special agreements. The towers testify to the revival of more complex building methods and materials, and the houses of the consorteria (association of noble families) that owned the towers clustered around them, forming the embryo of future buildings.
After the gradual transition to a communal form of government, Florence was provided with a new circle of walls in the 1170s. The new wall was rotated about 45° to the old one to include the villages that had sprung up around the city, and involved moving the Mugnone, used as a moat, further west. The Oltrarno remained undefended for the time being, or perhaps only protected by palisades.