The church was founded in 1137 on the site of another church from the 8th century dedicated to St Mary, which had been in turn erected over a Roman temple of the Clemence. The high altar was consecrated in 1185 and in 1187 the presbytery and the transept wings were completed. Due to financial troubles, the works dragged for the whole 13th–14th centuries. The bell tower was built from 1436 (being completed around the end of the century), while in 1481–1491 a new sacristy added after the old one had been destroyed by Bartolomeo Colleoni to erect his personal mausoleum, the Colleoni Chapel.
In 1521, Pietro Isabello finished the south-western portal, also known as Porta della Fontana. The edifice was restored and modified in the 17th century.
At least one photo a day