Seat of the Chamber of Commerce, Industry, Agriculture and Crafts, Palazzo della Mercanzia has governed trading and business activities of Bologna since the late 14th century. In 1384 the building of Carrobbio open gallery (today's Mercanzia) was initiated under the direction of Antonio di Vincenzo and Lorenzo Bagnomarino in order to group together three buildings used as customs and toll house. For the gallery and the preparation of the hewn stone four stonecutters were called from Florence. The building was completed in 1391, but the elegant palace needed an extension in 1439 and restoration in 1484 following the fall of the de' Bianchi tower. In 1888 - 90 it was reintroduced, also in its polychrome traits, under the direction of Rubbiani and Tartarini. It was rebuilt in 1949 after a live bomb blasted nearby had made half of the façade collapse. Built in brick and Istrian stone, the façade shows two deep Gothic arches, uplifting it, as further highlighted by the raising of the level under the porch with the respect to the surrounding square. Over the arches, a small marble balcony juts out between the two mullioned windows, from which the judges of the merchants' court would read their sentences. An elegant spire rises above the balcony covering one of the dovetail merlons of the battlements on top of the building. According to local tradition at the stroke of the bell called "Lucardina" bans and sentences of the merchant's court were read out-loud from this marble canopy. Instead the culprits of fraudulent bankruptcy were chained to a post placed before the central pillar of the gallery to be pilloried. The rooms and ambulatories of the building, despite the changes brought about with the passing of time, have kept the beauty of masterpieces untouched.
In Via Castiglione, on the wall of Palazzo della Mercanzia, a plaque commemorates the exemption from duties granted at the beginning of the 15th century to the students of the University of Bologna, which is evidence of the "Studio" prestige in municipal life.