In the very composite picture of powers, the main features of which were unquestionably represented by several important feudal families and by the Bishop of Arezzo, a new element must be added: the nascent autonomous power of the Italian city-states (Communes). The contessa Matilde had no sooner died than several cities had already made themselves into autonomous institutions. In Arezzo, the power had been held by consular magistrates since 1098, to the point that, from that moment on, the aristocracy who had fought over and divided up the valley by tying up roads, bridges, passes and rivers began to have to consider the presence of serious antagonists. In the end, they had to succumb in the face of the formation of the new institutional realities, that were "germinated in the flourishing and dynamic mercantile cities, the ladies of the plains" (Manneschi, 1921: 20-21).
Even if assailed from several parts and above all by Florence, which gave rise to an unstoppable expansion of its dominion in the direction of Arezzo, feudalism nevertheless maintained its positions of power for a long time, and perhaps these were never completely dissolved until the modern age.

In 1219, the Counts Guidi had to underwrite weighty pacts with the Florentines, on the basis of which they undertook to "give free entry, accommodation and exit in the said castle and keep of Montemurlo to whoever and whenever the Florentines wish". In addition to this, they had to accept the Florentine presence also in other strongholds located on their lands. In fact, the document stipulated that "for the complete safety of observation,

besides the debt and mortgage of the Castle of Montemurlo, they mortgage also to the Florentines the castles and jurisdictions of Montegnalchi, Loro, Pozzo, Lanciolina, della Trappola et omnia alia castra, terras possessiones, homines". Starting from the last decade of the 13th century, the Counts Guidi appeared to be in full deterioration, first of all because the cities - and Florence in particular - had progressively eroded their domains. In 1293, the Florentines took several fortresses away from the Guidi family and also the Castle of Loro. The latter returned shortly afterwards to Guidi control even if, in a continuous overturning of political destinies linked to the bitter conflict between the Guelphs and the Ghibellines, Florence finally succeeded in prevailing. It returned definitively in possession of Loro, as was established by the commission of 19 August 1306. From that moment on, having become a part of the Florentine territory, Loro was governed by a functionary ("podestŕ") nominated by the ruler while also Arezzo became a subdivided city of Florence in 1337. Despite this presence, however, the ancient feudal power still remained strong. Also the matter of the Castle of Trappola was included in the struggle undertaken by Florence to impose its predominance in the zone.

Trappola, on the slope of Pratomagno, was a castle that belonged to the Counts Guidi during the 13th century. In 1323, it was taken away from the dominion of the Pazzi family of Valdarno, who had been in possession of it for some time, to be handed over to Florence, which placed a garrison there. However, the Pazzi family allied itself with the Ubertini family, and re-conquered it.. The castle was then the object of further disputes also in subsequent moments.

The political instability and the recurring incursions of troops began to diminish with time, and this regained security certainly acted as a background to a penetration that was no longer just military and political on the part of the Florentines (or Aretines), but was above all of the citizen land owners. Towards the end of the 15th century, in fact, we find in these zones a reduced peasant ownership in minimum terms, in favour of that of the rich exponents of the emerging citizen classes and, also, a conspicuous ecclesiastical property with a considerable diffusion of shareholding contracts. In 1642, the first statutes of the community were drawn up.