The church was built between the end of the XI and the beginning of the XII century near the site of the martyrdom of San Donnino and was considered an important stop on the Via Francigena along the pilgrimage route to Rome. The statues and reliefs in sandstone of the lower part of the walled façade were sculpted by Benedetto Antelami and the masters of his workshop following a program of iconography that intertwined biblical and pilgrimages subjects and representations of historical characters with the stories of the life of San Donnino. The adjacent Diocesan Museum founded in 1999 preserves and enhances works of art coming from the territory of the Diocese. In the ‘Treasure of San Donnino’ are preserved medieval sculptures and goldsmith works of exceptional value, such as Benedetto Antelami's ‘Maestà mariana’, a Romanesque baptismal font, the chalice of San Donnino and an ewer in the shape of a dove, a favorite piece of historian Jacques Le Goff.