Palazzo Doria Pamphilj and the adjacent Collegiate Church of Our Lady of the Assumption are today the only surviving structures of the ancient settlement of the town of Valmontone which was almost entirely destroyed by bombing. Later rebuilding then greatly altered the original lines of the buildings.
The Valmontone Town Council along with the relevant official institutions have been restoring the structure and paintings of the piano nobile (first floor) for several years now. The building has been earmarked for the University of Rome, La Sapienza, and already houses several of its research centres.
It was Prince Camillo Pamphilj, nephew of Pope Innocent X, pontiff at the time, who decided to build the majestic palace in the midst of an urban complex which included guest facilities, armoury, stables, granary, prisons, a market square and artisans' workshops. It was a very ambitious project, defined at the time as a 'Pamphilj city' and represents one of the last executions of the Renaissance theory of the ideal city. Building work started in 1654 and finished in 1670.
The architectural plan, which was modified from Camillo's original designs during construction, appears to be a way to bring the characteristics of a noble palace, a country residence and a fortress together. The compact, sealed nature of the building, which is placed on the highest level of the town, is a reminder of the strategic look out positioning that the complex must have inherited from the previous medieval castle. The external facade has a massive, sloping, rusticated base and four rows of windows framed by cornicing in the sandstone.
The fresco cycle on the piano nobile was painted between 1657 and 1661 and an extremely important example of Roman art in the mid 17th century. Although the frescoes have not been well preserved, a great deal of the decoration has now been restored to good visibility.
The decoration in the eleven rooms is concentrated on allegories of the four elements and four continents, excluding the Prince's salon and the two minor rooms. The frescoes were painted by important artists such as Pier Francesco Mola, who was entrusted with the direction of the work, Gaspard Dughet, Guglielmo Cortese, Francesco Cozza and, not least, Mattia Preti.