The palatine basilica di Santa Barbara , court church of the Gonzaga family, was built, together with the bell tower, by Duke Guglielmo between 1562 and 1572, based on a design by Giovan Battista Bertani.

The façade is characterized by three arches, surmounted by the pediment, which lead into the entrance vestibule, above which, inside, there is a large choir loft for the musicians.
The church inside is enriched by valuable works of art: the Martyrdom of St. Barbara by Domenico Brusasorci, from 1564 and two large altarpieces in the main chapels by Lorenzo Costa the Younger.

But above all it was soon equipped with a remarkable musical chapel for which the best musicians of the time wrote, from Palestrina to Contino and then Gastoldi and Giaches de Wert. Linked to the basilica is also the figure of Claudio Monteverdi, in the service of the Gonzagas from 1590 to 1612. The church was equipped with a precious organ, built by Graziadio Antegnati in 1565, which is still in use today thanks to the 2006 restoration by Giorgio Carli.