The first cathedral arose in the year 708 under Bishop Vincent and stood in the same location as the present cathedral. It was built in the pre-Romanesque style and possessed three naves supported by marble columns whose capitals bore the effigy of the aquatic flounder, representing the city’s coat of arms, until, in 1200, the building was remodeled in the Gothic style and remained so until 1659. Because of the constant restorations to which it was subjected and the age of the building, in the same year it was decided to demolish it so that a new cathedral could be made out of it, the work on which began on March 25, 1659, under the impetus of Cardinal Legate Giuseppe Renato Imperiali. Nevertheless, from the laying of the foundation stone until the excavation of the foundations and masonry work more than 35 years passed, being solemnly consecrated on April 12, 1740 by Bishop Giovanni Cavedi, always keeping faith with the original design of architect Angelo Cerruti who conceived it in the Baroque style. Finally, on October 13, 1961, the cathedral was elevated to the dignity of minor basilica by Pope John XXIII.
The facade is entirely of brick, except for the capitals, pilasters, plinths of the pedestals and the median cornice, which are all of Istrian stone. Adjacent to the cathedral stands the bell tower, the work of architect Giorgio Fossati, built in 1751 but ruined to the ground a few years later in 1757. It was later rebuilt and completed only in 1868 on the huge base of the old bell tower, which remained unharmed by the collapse. The interior structure of the cathedral has a single nave with six chapels on each side inside which are valuable paintings by artists of the Bolognese School of painting such as Biagio Bovi (18th century), the wooden crucifix by the Ferrarese sculptor Germano Cignani and the sculpture of St. Lucy of the Venetian school (15th century). Of considerable interest appears the apse decorated with a scenic 18th-century marble altar with winged angels and a wooden statue of the patron saint Saint Cassiano. All around the apse also runs a wooden choir in a double row of stalls, a gift from the bishop of Arcano. Finally, placed above the entrance portal is the organ, built in Modena in 1728.
