The municipality of Castelfiorentino is in the province of Florence, in the territory of the area Empolese-Valdelsa, 50 metres above sea level, with a population of about 17000 inhabitants.
Castelfiorentino is between the central part of the Arno Valley and the Northern part of Elsa Valley, on the territory that was called a "street territory" in the Middle Ages. As many other small villages of the medieval Tuscany the first complex of the village was born on one of the ways of pilgrims and wayfarers coming from the North of Europe and going to Rome. It took the name of Castelvecchio because it was near an old Roman settlement called Timignano. Castelvecchio was a fortified castle within two sets of walls that enclosed the parish of St. Ippolito within the first walls, and Borgo d'Elsa and Borgo Nuovo within the second walls. It had five gates surmounted by towers, and only two roads that led to the present Piazza del Popolo. It was a feud of the Cadolingi and later of the Conti Alberti.
In the 12th century the bishop of Florence took possession of it, dragging it to the events linked to the conflicts between the Church and the Empire, Guelph and Ghibelline and between Siena and Florence. Its geographical position between Florence, Pisa and Siena was decisive in the transformation of the village into a nerve centre for military activities. The village became one of the strategic outposts of these struggles and from 1149 it took the name of Castelfiorentino, getting the seat of the Podestà and the possibility to have the lily, symbol of the chief town, sewn on its gonfalon. In Castelfiorentino, in 1260 after the battle of Montaperti, the peace agreement between Siena and Florence was ratified.
The importance of this centre decreased with the period of the political and military crisis of the large Tuscan municipalities. In 1521 it was besieged and plundered by the Spanish militia. However, in the 18th century it was involved in the new ascent of Tuscany under the rule of the Lorena and it obtained again its status of residence of the Podestà, with jurisdiction also on Certaldo and Montaione. It was annexed to the Kingdom of Italy and in 1868 it became the chief town of Mandamento. In 1902 Castelfiorentino was one of the first municipalities that gave the lead of the administration to the candidates of the Socialist Party.
The central position of the town in comparison with the great theatres of the Italian artistic scene strongly influenced the town planning structure. Many works can be admired in the town: Piazza del Popolo, with the Municipal Palace, the Collegiate church of St. Lorenzo and Leonardo and the Sanctuary of St Verdiana .