After the defeat and death of Corrado III Trinci (June 1441), the palace became the seat of the Priori del Popolo and the papal government of Foligno.

It was built by Vincenzo Vitali on a draft of Odoardo Poggi, amended by Sigismondo Ferretti.The arcaded inner courtyard reflects the problems the architects faced when they wanted to save as much as possible from the pre-existing structure.

The steep Gothic staircase (Scala Gotica) was built over three Romanesque cross vaults between 1390 and 1400, when the palace still belonged to the wealthy merchant Giovanni Ciccarelli.

The concept of these fresco cycles probably came from Francesco Federico Frezzi, the bishop of Foligno and author of the Quadriregio, a poem of the four kingdoms Love, Satan, the Vices, and the Virtues.

The authorship of the frescoes was attested by Lodovico Coltellini, a scholar who saw in 1780 two receipts to Ugolino Trinci by Gentile da Fabriano for painting the halls.

The Hall of Liberal Arts and of the Planets (or Hall of Stars) takes its name because its frescoes represent the Liberal Arts : the Trivium (grammar, rhetoric, logic and philosophy) and the Quadrivium (music, geometry, astronomy, and arithmetics) and the planets: (Moon, Mars, Mercury, Jupiter, Venus, Saturn and the Sun - the latter two are missing) The other side of the room shows the different Ages of Man (infancy, childhood, adolescence, youth, adulthood, deterioration, old age, decrepitude) and the Hours of the Day.

The provision of the planetary system does not conform to the actual position of planets in the heavens, but follows a chronological trend that relates to the day of the week.

The practice of decorating palace walls with a series of famous men was widely known during the Middle Ages and lasted well into the 16th century.

They represent Romulus, Julius Caesar (lost), emperor Augustus, Tiberius, Lucius Furius Camillus, Gaius Fabricius Luscinus, Manus Curius Dentatus, Titus Manlius Torquatus, Cincinnatus, Marcus Marcellus, Scipio Africanus, Muzius Sceva, Cato the Younger, Gaius Marius, Publius Decius, Nero, Fabius Maximus, Caligula, Pompey and Trajan (the last three are lost).

The concept of these frescoes came from the humanist Francesco da Fiano (1350 ca.-1421), who was inspired by the model of ancient biographies of famous men (De viris illustribus) by Petrarch, used in the decoration (today lost) in the great hall of the palace of the Carrara (Loggia dei Carraresi) in Padua.

[2] Some archaeological artifacts are also on exhibition in this room, most notably a marble slab showing a quadriga race in the Circus Maximus, Rome.

The Hall of Sixtus IV was redecorated during the reign of pope Paul III Farnese (1535-1546), most probably by the painters Lattanzio Pagani and his gifted assistant Dono Doni.

The walls of the corridor, linking the palace with the cathedral of San Feliciano, is frescoed with the Heroes of Ancient Times (Ciclo dei Prodi).