The religious building is located on the edge of the Stampace district, in a hilly portion made flat close to the walls of Castello.
The institution of the religious order of Clarisse nuns dates back to 1212 and dates back to the will of Francis of Assisi. In a chronological period between the end of the 16th century and the first quarter of the 13th century, Cagliari welcomed the Poor Clares in Stampace to the monastery, now defunct, which took on the title of Santa Chiara, probably founded earlier by nuns of different rules. The cloistered convent of the Poor Clavers was administered by the friars of the nearby San Francesco di Stampace until 1587, when it entered, at the behest of Pope Sixtus V, under the auspices of the archepiscopal canteen. In 1895, following the enactment, in 1866, of the second law suppressing religious orders, the monastery was now administered by the Fund for Worship, but it was still in vogue, even though it housed only seven nuns compared to the twenty-nine certified by Martini in 1841; in 1897 it became part of the Municipal State. Instead, it was abandoned during the twentieth century: in 1911 it became the property of the Finance Authority, to return to the Municipality in 1922 and was, finally, seriously compromised by the aerial bombings of 1943, followed by the demolition of most of the ruins and, from 1957, the establishment of the local market. The archaeological excavation and restoration carried out recently, between 1980 and the mid-nineties, by the Archaeological Superintendence and the Superintendence of BAPPSAE of Cagliari and Oristano have specified the dating hypotheses relating to the complex: the church is seventeenth-century, although built on a previous Romanesque hall, while the existence of the convent has been indirectly attested since the last decades of the XIII century, at the time of the Pisan domination. It is therefore likely that the area housed an older monastic complex, on which the Franciscan one was then inserted.
As far as the church of Santa Chiara is concerned, archival documents have confirmed the insistence, most likely on the same site, of a small pre-existing chapel: in fact, the first documentary attestation of the existence of a church dedicated to Santa Margherita dates back to 1256, whose date of foundation is unknown. Even in 1861, Spano claimed that the current building was built in the seventeenth century with the title of Santa Margherita, according to what it could detect from the inscription S MARGARITA V M 1690, engraved on the lintel of the side portal and still visible. However, some scholars have recently hypothesized the existence of two separate churches, although close in space: the church of Santa Chiara that still exists and, in fact, that of Santa Margherita, demolished in 1947.
The building has a single large nave with side chapels and an elevated rectangular presbytery, reduced in height and width compared to the classroom; the interiors show abundant stucco decoration. The sober plastered façade ends with an annoyance “like a carabiniere's lamp”, that is, a doubly inflected arch, in this case ending in volutes; it also has two quadrangular openings symmetrical with respect to the central portal, surmounted by a small niche with a basin decorated in a shell, formerly housing a statue. The aisle has been turned round to square, punctuated by undercuts set on grooved piles set up by the Corinthian capital, placed at the external buttresses; the vault insists on a protruding, notched frame above a decorated frieze. The choir, where the nuns participated in liturgical functions, is based on a lowered arch and has a niche decorated with a shell, as well as a balustrade adorned with a coat of arms. At the same time as the erection of the church, in 1690, some burials were placed inside it covered with marble tombstones, two of which, dating back to the third quarter of the seventeenth century, were recently moved to a counterfaçade; at the beginning of the 18th century, the sacristy was finally built next to the presbytery, housing a tomb reserved for the burial of nuns.

Bibliography
P. Martini, Ecclesiastical History of Sardinia, III, Cagliari, Royal Stamperia, 1841;
G. Spano, Guide to the city and surroundings of Cagliari, Cagliari, Timon, 1861;
F. Corona, Guide to Cagliari and its surroundings, Bergamo, Italian Institute of Graphic Arts, 1894;
R. Salinas, “The architecture of the Renaissance in Sardinia — The first examples”, in Sardinian Studies, XIV-XV, part II, 1955-57; Santa Chiara.
Restorations and discoveries, edited by A. Ingegno, Cagliari, Pisano, 1993;
M.G. Meloni, “Notes on the presence of the Poor Clares in Sardinia in the Middle Ages”, in Bibliographic Bulletin and Archival Review and Historical Studies of Sardinia, XI, fasc. 18, 1994; M. Pintus, “Architecture”, in Cagliari Historic Quarters. Stampace, Cinisello Balsamo, Silvana, 1995;
M. Dadea - S. Mereu - M.A. Serra, Archdiocese of Cagliari, series “Churches and sacred art in Sardinia”, Cagliari, Zonza, 2000.