The building occupies a large area between the Embankment and Piazza Palazzo, in the historic district of Castello. It is currently the seat of the Prefecture and the Provincial Council of Cagliari.
The Palace was built at the time of the Pisan presence and was used as viceregal headquarters in 1337 by the will of Peter of Aragon, ruler of the “Regnum Sardiniae et Corsicae”.
Over the centuries, it underwent various structural changes aimed at improving the functional characteristics required by the ever new and diverse offices and institutions arranged by the governors of the Kingdom. In its rooms, in addition to the private apartments of the members of the viceregal court, the Royal Audience and the direction of the island's military defense were located. Only starting in 1720, with the transition from the Habsburg monarchy to the Savoy monarchy, were there substantial changes, which involved both the renovation of the interiors and the reconstruction of the façade.
In 1730, on the design of the chief engineer De Guibert, the portal, the atrium and the honorary staircase were completely rebuilt and work began to embellish the Royal Audience Hall. The engineer Della Vallea (active in Cagliari from 1735 until his death in 1744) was responsible for the renovation of the main floor with the arrangement of a series of rooms on the O front; while the façade, which an inscription in the center of the façade in line with the main door says ended in 1769 by the will of the viceroy Ludovico De Hallot, is due to a design by Saverio Belgrano di Famolasco, who also designed the E-shaped façade, above the embankment.
From 1799 to 1815, following the French occupation of Piedmont, the palace became the home of the Savoy court. It then passed to the Provincial Administration, which bought it in 1885 from the State property.
The main façade, characterized by its extension on the longitudinal plane, consists of three orders of windows framed by monumental stone piles, which extend to full height and rest on a plinth made of strong stone that follows the inclination of the ground. The windows on the main floor, surmounted by projecting frames, open onto curved balconies, supported by shelves and wrought iron railings. A tall parapet with a frame concludes the upper part of the building. The rhythm given by the alternation of windows and pilasters is interrupted by the central portal, with a round arch and framed by two Doric columns that support the balcony above, on which a curved French door opens bearing the inscription CAROLUS EMANUEL III PROREGE D. LUDOVICO DE HALLOT COMES DE HAILES REFECIT ORNAVIT MDCCLXIX. The atrium leads to the staircase that leads to the main floor; then you pass, through the room with the portraits of the viceroys, into the provincial council hall, built in its current configuration at the end of the nineteenth century and decorated between 1893 and 1896 by Domenico Bruschi. The second floor is accessed through two service stairs. Prospect E, which overhangs the Embankment walk, is divided into semi-obliterated arches concluded by windows.

History of studies
The architecture of the palace is the subject of a summary sheet in the volume by Salvatore Naitza (1992), while the decoration of the Council Chamber is described in that of Maria Grazia Scano (1997), both from the series “History of art in Sardinia”.

Bibliography
G. Spano, Guide to the city and surroundings of Cagliari, Cagliari, Timon, 1861;
D. Scano, Forma Karalis” Cagliari, Societa Editrice Italiana, 1934;
M. Cabras, “The works of De Vincenti and the first Piedmontese military engineers in Sardinia in the period 1720-1745", in Proceedings of the XIII Congress on the History of Architecture. Sardinia), I, Rome, Center for Studies for the History of Architecture, 1966, pp. 291-310;
E. Coiano, “The Palace of the Province”, in Almanacco di Cagliari, 1976, without pages;
S. Naitza, Decorations in the Viceregio Palace of Cagliari, Cagliari, Provincial Administration of Cagliari, 1981; S. Naitza, Architecture from the late 17th century to purist classicism.
Nuoro, Ilisso, 1992, page 21;
M. G. Scano, Nineteenth-century painting and sculpture. Nuoro, Ilisso, 1997, page 162;
The Royal Palace of Cagliari. Nuoro, Ilisso, 2000.