Iglesias lies at the foot of Mount Marganai and is known for the mining activity that has characterized it in past centuries. The territory is rich in archaeological sites that document the continuity of the settlement since prehistoric times. The presence of the cruciform church of San Salvatore attests to its attendance in the Byzantine era. The center became especially important starting from the 13th century, when it took on an urban physiognomy with the name of “Villa Ecclesiae”.
The urban history of Iglesias, originally called 'Villa Ecclesiae', is long and complex. A fortified Pisan settlement in the 13th century, all defensive equipment was dismantled in 1289, following the rebellion of Guelfo di Donoratico against the Republic of Pisa. However, the city, already administered by means of the “Brief of Villa di Chiesa”, was soon restored to full efficiency: it is known that in 1302 it was under the administration of Pisa. With the arrival of the Aragonese troops in 1323, combined with those of the kingdom of Arborea who wanted to conquer the Pisan possessions on the island, Iglesias's situation became difficult. It was the first city to face the attack of enemies, also attracted by the silver mines of Villa di Chiesa. The surrender to the Aragonese troops came on 14 January 1324, after seven months of fighting. Having become a fief of the Carròs family, Iglesias found himself in the middle of the war between Aragonese forces and Arborense troops, which broke out for control of the island in the middle of the 14th century. Only in 1479, after more than a century of struggle, did Iglesias become part of the effective patrimony of the Crown of Aragon.
From a series of dispatches sent in 1308 to the Aragonese ruler James II the Just, the type of fortification of Iglesias is known in sufficient detail. The inhabited nucleus was enclosed by a circle of tall crenellated walls, interspersed with 20 towers to form a polygonal plan; in front of the curtain of walls there was a wooden palisade, with a defensive function, reinforced by a moat that was used to keep troops and war machines away. The walls had the peculiarity of being made of mixed stone arranged in horizontal courses, creating an inhomogeneity that guaranteed great resistance to attacks.
Access to Villa di Chiesa was through four doors: Porta Maestra, in front of the road to Cagliari, Porta Castello, now near the cemetery, Porta Sant'Antonio, on the road to Fluminimaggiore, Porta Nuova, on the road to Gonnesa. Between Porta Castello and Porta Sant'Antonio there was the Salvaterra hill, where the castle was built. Due to the war events that involved it, the city of Iglesias with its walls was damaged several times and rebuilt with appropriate modernization. To this day, the medieval city walls are clearly visible for long stretches.

History of Studies
On the Walls of Iglesias, first of all, the article by Foiso Fois entitled “The medieval city and the castle of Salvaterra di Iglesias”, first published in 1963 and then included in the volume “Castles of Medieval Sardinia”. Alfredo Ingegno's book dates back to 1987, in which the restorations are promptly reported. The fundamental works edited by Marco Tangheroni are historical: “The City of Silver” and “Studies on Medieval Iglesias”.

Bibliography
F. Fois, “The medieval city and the castle of Salvaterra di Iglesias”, in Historical and Legal Studies in Honor of Antonio Era, Padua, 1963, pp. 170-178; F. Fois, “A treasure chest of history. The castle of Salvaterra di Iglesias”, in Almanacco di Cagliari, 1979, without pages;
A.M. Oliva-O. Schena, “The second arborense capture of Villa di Chiesa in 1391", in Middle Ages essays and reviews, 9, 1984, pp. 119-134;
M.M. Costa, “Officers of Peter the Ceremonious at Villa di Chiesa”, in Studies on Medieval Churches, Pisa, 1985, pp. 193-214; M. Tangheroni, The City of Silver. Iglesias from the origins to the end of the Middle Ages, Naples, Liguori, 1985;
A. Ingegno, Iglesias. A century of protection of architectural heritage, Oristano, S'Alvure, 1987;
F. Fois, Castles of medieval Sardinia, edited by B. Fois, Cinisello Balsamo, Amilcare Pizzi, 1992, pp. 63-70.