Seat of the Free Commune, it was built in various stages: the first (1293-97), the part corresponding to the Sala dei Notari, is by Giacomo di Servadio and Giovannello di Benvenuto. The second (1335-53) arrives above the arch of Via dei Priori and Via della Gabbia. The third (1443) and the remaining stages (up until the 18th cent.) proceeds along the Corso. Its construction incorporated various pre-existing buildings, including two towers, visible along Via della Gabbia and Corso Vannucci (street number 21). Well worthy of a visit are the atrium, the bell-tower and the 14th century portal with statues of the patron saints Lorenzo, Ercolano and Costanzo, preserved in the original at the National Gallery of Umbria. The higher floors of the palazzo host one of Italy’s richest collections, in terms of number and quality of the works of art dating from the 13th to the 19th centuries.

The north facade of the palace is the result of two distinct building periods: the left section, characterised by a series of mullioned windows and an imposing Gothic portal leading to the Sala dei Notari (Hall of Notaries) was built between 1293 and 1297, while the right section, with its triple-arched portico, built on the site of the church of San Severo di Piazza, was added in 1335 ca. The interior was hugely altered during the Church’s dominion, and was restored to its original state after 1861. The wide fan-shaped staircase was added in 1902 to replace the two-flight medieval one. 
Above the portal are bronze copies of the griffin of Perugia and the Guelph lion (the originals, 1271-81, from the fountain by Arnolfo di Cambio, are inside the palazzo). From the massive ledges hang the chains which the Perugian people took from the gates of Siena (after the battle of Torrita in 1358).

HALL OF THE NOTARIES - Magnificent hall supported by eight large arches, originally used for the people’s assemblies during the Free Commune, in 1582 it became seat of the powerful “Arte dei Notai” association, from which it takes its present name. Only a few fragments remain of the original 13th-14th century frescoes. Most have been painted over or incorporated into the legends, tales, bible stories and coats of arms, including those of the Captains of the People and the Podestà, painted by Matteo Tassi (1885). On the back wall is the coat of arms of Braccio Fortebracci, while along the side walls are 16th century stalls and seats. Totally altered during three centuries of Papal rule, the church was restored to its original state after 1861. At the top of the external staircase is the Sala della Vaccara which houses a fresco painted by Tiberio di Assisi in 1568.