The edifice was built around 1200 as the seat of the local podestà, the various functionaries of the commune. It stands on the Piazza Maggiore, near the Palazzo Comunale and facing the Basilica of San Petronio. Proving insufficient for the massive participation of the people in the city's government, it was in 1245 flanked by the Palazzo Re Enzo, over which stands the Torre dell'Arengo, whose bell was used to call the people during emergencies.