The territory around Colle was decreed Nullius Diocesis, which means it did not belong to a diocese and thus depended directly on the pope, receiving important privileges as a result, even though it was part of the territory of the diocese of Volterra. The archpriest of Colle was recognized as having the same dignity as a bishop and exercised his authority over the whole territory. He could consecrate churches and chapels, issue edicts, formulate excommunications, and carry the crosier in the celebration of Mass and Solemn Vespers. Between the eleventh and twelfth centuries, as a consequence of continual raids, the populations of the neighboring castles and hamlets moved inside the castle of Piticciano, resulting in its demographic growth and the subsequent establishment of a commune. Colle di Val d’Elsa took on its own identity at the same time as other towns in the upper Elsa valley such as Casole, San Gimignano, and Poggibonsi. Its economic, social and cultural development was favored by several important factors like its central position among the great powers of Tuscany (Siena, Florence, and Volterra) and the presence of the Elsa river which, thanks to a system of canals, permitted the distribution of water to all the nerve centers of the town, generating a constant source of energy for the mills. Moreover, the presence of the Holy Nail made Colle a fundamental stop along . . .