The construction of the various wings of Palazzo Colonna lasted for five centuries and this led to the overlap of different architectural styles, both exterior and interior, that characterize it and reflect the different epochs of belonging.

From 1300 to 1500 it presented itself as a real family fortress. Oddone Colonna, elected pope on 11 November 1417 and assumed the name of Martin V, destines the Palace to the Pontifical See and lives there from 1420 to 1431, the year of his death.

In the austere halls of Palazzo Colonna, Pope Martino V plans and realizes in ten years a great plan of cultural, urban and administrative renaissance of the city of Rome, which lay in ruinous condition after the tormented period of the captivity of Avignon and of the Western schism. In 1527, during the sack of Rome by the troops of the Emperor Carlo V, Palazzo Colonna is one of the few buildings that are not burnt thanks to the good relations of the family with the Empire...