This church was initially dedicated to St. Giles, but was later renamed after the Patron Saint of the city, St. Homobonus, who actually died in the church during a Mass in 1197.

The interior of the church was at one point completely transformed with spectacular frescoes, of which the most noteworthy is in the cupola, "The Glory of St. Homobonus", a fresco that stands out for the illusions it creates.