Ponte d’Arbia has been documented since the early Middle Ages as the ancient Via Francigena is located along the route. In particular in the itinerary of Sigeric, archbishop of Canterbury, the locality represented the XIV stage (Submansio) and was then defined Arbia. On August 24, 1313, less than a kilometer from the town, Henry VII of Luxembourg, emperor of the Holy Roman Empire, of which Dante also speaks in the Divine Comedy, died. According to historical sources, the emperor was poisoned during communion by a friar from the convent of Buonconvento. The current bridge that gives the town its name was built by the Municipality of Siena in 1388, and rebuilt in 1656 under Prince Mattia de ‘Medici, governor of Siena

Unique for its particular and original shell shape, it is renowned all over the world for its beauty and architectural integrity, as well as for being the place where the Palio di Siena takes place twice a year. For an ancient convention, the square and the Palazzo Pubblico do not belong to any district. The space that would become the present square was, at the origins of Siena, a land reclaimed to allow the outflow of rainwater, as a semicircular head of the Montone valley, between the Santa Maria hill and the ridge that goes towards Porta Romana. The nucleus of the city in formation was located higher up, in the Castelvecchio area and the future “Campo” was a space for markets, just lateral to the main communication roads that passed through the city and located exactly at a crossroads. Here the routes to Rome to the south-east still meet today, to the sea to the southwest and to Florence to the north. The history of the square is strongly intertwined with that of the construction of the Palazzo Comunale, or Palazzo Pubblico, which overlooks it