Cagliari, founded between the 8th and 7th centuries BC by the Phoenicians, experienced important periods of occupation in the Punic, Roman, Byzantine and Judicial ages, becoming the capital of the Kingdom of Sardinia in the 14th century. Passed from the Aragonese to the Spanish, then to the Piedmontese, it preserves significant monumental traces of its past. Among these are the ancient towers and walls, which surround Castello and dominate the historic districts of Villanova a E, Stampace a O and della Marina a S.
During the Viceroyalty of Dusay (1491-1508), a small bastion was erected in the Castle in front of the church of Santa Croce, another on the site of the current Balice and the bastion of the Bona Fountain, in the area occupied today by the Bastion of Saint Remy. Lower down, the bastion of La Leona was built towards the ancient Pisan antemural and, towards N, to defend the Buon Cammino area, a bastioned front faired with vertical walls and a related door. This last work was harshly criticized for its lack of efficiency.
Later, Viceroy De Cardona, in 1534, had two bastions built in the port, called Levante and Sant'Agostino respectively, to E and O, whose shape or wall technique is unknown. In the Castle, he also erected a stretch of wall between the Elephant Tower and the Mordent Tower (Santa Croce area). The works of the port were resumed by the architect Pons the following year; he designed two bastions inside the river and then connected them to the two embankments of Sant'Agostino and Levante with curtain walls that surrounded the seafront of the Lapola district.
Between 1552 and 1571, a new defensive reorganization was carried out by the Cremonese architect Capellino, who built, in the O shape, the bastion of Sant'Antonio, with part of the wall of the Balice; in Santa Croce, a half bastion was built to replace that of Dusay, bordering the San Gregorio pit and grafting into the walls at the height of the Purissima. Finally, he built a pin-shaped bastion to defend the tower of San Pancrazio. New modifications were carried out under Jacopo Palearo Fratino, who enlarged the pliers of San Pancrazio, transformed the mezzobaluard of Santa Croce into a pentagonal bulwark and completed the bastion of Sant'Antonio (Balice).
Giorgio Fratino, Jacopo's brother, in Cagliari since 1573, completed his projects by expanding the bastion of Sant'Agostino and completing the walls of the Marina. A new bastion towards Villanova was built under Captain Arcaine in 1638, while around the middle of the century the fortifications of the port and the marina were reorganized. The last Spanish intervention, in 1707, concerned the extension of the pier and the construction, on the end, of the fort of San Giacomo.

History of studies
Starting with the entry edited by Vittorio Angius (1836) for the Casalis “Dictionary”, there have been numerous studies on the city of Cagliari. Canon Giovanni Spano (1861) describes it in his “Guide”, which is still fundamental today for the knowledge of the historic center. In the twentieth century, Dionigi Scano (1907), then Raimondo Carta Raspi (1933) suggested a study methodology, which continued after the war with Angela Terrosu Asole (1959). Evandro Putzulu (1976) delves into the problem of the origins of the settlement in the Castle. Renata Serra (1976) dedicates her attention to Giovanni Capula, architect of the two surviving towers. The most up-to-date research was conducted in the Eighties by Franco Masala (1985), Emerenziana Usai and Raimondo Zucca (1986), Foiso Fois (1992), Roberto Coroneo (1993) and Marco Cadinu (2001).

Bibliography by
D. Scano, Forma Karalis, Cagliari, Societa Editrice Italiana, 1934;
E. Putzolu, “The problem of the origins of Castellum Castri di Vallari”, in Archivio Storico Sardo, XXX, 1976;
F. Fois, Spanish Towers and Piedmontese Forts in Sardinia, Cagliari, La Voce Sarda, 1981; R. Conde y Delgado De Molina, Castel de Caller.
Cagliari Catalan-Aragonese, Cagliari, Edizioni della Torre, 1984; S. Casu-A.
Dessi-R. Turtas, “Jacopo Palearo Fratino's design for the fortified system of Cagliari”, in 17th and 18th century Art and Culture in Sardinia. Proceedings of the National Conference, Naples, 1984;
S. Casu-A. Dessi-R. Turtas, “The defense of the Kingdom: the fortifications”, in Sardinian society in the Spanish Age, Quart, Musumeci, 1992;
F. Russo, The coastal defense of the Kingdom of Sardinia from the 16th to the 19th century, Rome, Army General Staff, Historical Office, 1992;
F. Segni Pulvirenti - A. Sari, Late Gothic and Renaissance-influenced architecture. Nuoro, Ilisso, 1994, sheet 13.

How to get there
The walls of Cagliari encircle the historic district of Castello, the most important of the city, around the entire perimeter, and include two completely surviving towers: that of San Pancrazio and that of the Elephant.