Sce Dionisii was known as the pieve of San Genesio. The presence of this church is attested in a document of the Arezzo church from 715, describing a council attended by several bishops from Tuscany and an envoy of Lombard King Liutprant.
Some of the remains of San Genesio (also called Burgo San Genesio) have been excavated by the departments of archaeology of the University of Siena and Pisa. In addition to being located between the river Arno and Elsa, the site is situated at the crossroads of the Roman road via Quinctia and the via Francigena, and indicates a presence since the paleolithic era. The excavations have brought to light numerous Early Middle Ages structures, an ancient necropolis dating from the time the Byzantines and Lombards were fighting for the possession of the peninsula, and the remains of the ancient church. One particularity of this church is its 12th and 13th century marble inlay techniques; an artistic trend that took place virtually in Tuscany alone. Applied to large surfaces (such as baptismal fonts, pulpits, etc…), the marble was usually inlaid with a colored stone like serpentine which highlighted and brought out patterns and symbolic figures. (Arte Magistri. Intarsio marmoreo in Toscana nel XII-XIII Secolo. Atti del Convegno di Studi, Empoli 30 Ottobre 2015)
Until the 13th century, San Genesio was the home of emperors and popes, and the seat of the Assizes. Slowly, the town lost its prestigious position and was completely assimilated by San Miniato by 1248.
Interesting fact: since 1969, and during the last three weeks of November, San Miniato hosts a white truffle festival. The white truffle, also called king of truffles, is found in the area around the city.