The complete reconstruction of the church, during the XIIth century, on the site of an older religious building and its geographical position on the border between the plain of Lucca and Valdinievole, were particularly favourable for the growth of a village around it in the Middle Ages. The church has preserved its medieval structure with three aisles and its original decoration, with the exception of the apse end that was considerably readjusted in the XVIIIth century. The decorated capitals of the inner colonnade, the marble pulpit dating back to 1162 and the richly adorned façade are of particular interest. In the XVIIIth century the apse area of the church was reconstructed and the medieval side doors were replaced. The bell tower to the north of the church was built in 1840, according to an inscription on the wall.
The first information we have about the church of San Gennaro dates back to 873.