In white limestone, embellished by loggias and precious polychrome marble, the church dominates the piazza with the same name.
Originally built in the 7th century, in the location where the Roman forum of the city rose, it was, however, then entirely reconstructed by Alexander II around 1070, in the same period in which the the Cathedral was reconstructed, by the same architects and with similar characteristic styles close to the Pisa style.
Following there were additions and modifications: the bell tower is from the 12th-14th cent., in the 16th century windows were opened substituting the altar, from the second-half of the 19th century is the complete restoration.
The church is Latin-cross design, with semicircular transept and apse, covered with lunette barrel vaults; the façade, also polychrome, very pictorial, is embellished by four rows of loggias and mounted by a large statue of the archangel Michael beside two angels.
Romanesque columns with precious capitals enrich the interior of the church, in whose center is the very beautiful 18th-century pulpit with bas-relief; to admire is the original sculpture of the Madonna with Child by Matteo Civitali, (second half of the 1400's), whose copy is located in the corner outside of the church, the colored terracotta altar (1500) is dedicated to S. Lucia, the Madonna with Child by Andrea Della Robbia (end of the 15th-century), a table with four saints by Filippino Lippi.
