The inhabited area that had been growing, during the 13th century, outside the first nucleus of the castrum, on the slope facing the valley, was enclosed by a new wall circuit that also included the part called Borgo nuovo. The new extension of the walled part had reached the current Via Lungo le Mura, where the main gate opened, allowing issue of the road toward the bridge over the Elsa. In the middle of the 14th century, the road that reached the crossing from the main gate was already an extension of the town, called Borgo d’Elsa. In one portrayal of the time, it is described as follows: Burgo Else ad pedem castri, in capite Burgi Else, apud pontem Else de Castro Florentino, where the Borgo d’Elsa extended, from the walls of Castelfiorentino to the bridge over the Elsa. This was the maximum extension reached by the town in the mid-14th century. The large fortified village was considered by Florence among those strategically important: it was located on the border of the Elsa, and was affected by episodes of war for the next two centuries. In the second half of the 14th century, Florence systematically monitored, through its officers, the efficiency of Castelfiorentino, by ordering from time to time what was necessary for its maintenance. In 1349 the order was given for the transfer to the community of Castelfiorentino of one of the curtain towers that belonged to the parish, to prevent it from falling into enemy hands and being used against the castle itself. In 1359, Castelfiorentino was evaluated as having the capacity to accommodate as many as 200 knights, like the larger villages of the Valdelsa (Poggibonsi and San Gimignano), unlike Monterappoli and Pontorme, which could not accommodate even a single one. In the 1370s the men of Castelfiorentino, who had contributed to the war against San Miniato, asked Florence for exemption from duty taxes. During the military campaigns they had suffered crop damage, in addition to sustaining the obliged burden of restoring the castle walls, and only the tax exemption would have prevented the mass abandonment of the already impoverished and indebted population. The castle village of Castelfiorentino still appeared, during Leonardo’s time, in the form reached in the mid-14th century. In the famous bird's-eye view of the Valdelsa reproduced in map RL 12278 of the Windsor Collection, we can clearly see the profile of Castelfiorentino enclosed by a circuit of turreted walls. The walls had been restored repeatedly. In 1430, as we read in a report prepared by the podestà of Castelfiorentino, Benedetto di Piero Strozzi, the walls had collapsed in at least three points, and should have been repaired, but the economic conditions of the inhabitants at that time would not allow it. Nonetheless, Castelfiorentino during Leonardo’s time was still one of the castles characterizing the military landscape of the Valdelsa.