The Basilica of San Saturnino, one of the oldest early Christian monuments in the city of Cagliari, is dedicated to the patron saint of the city. The building dates back to the 5th-6th centuries AD and would have been erected on the tomb of San Saturnino, martyred in 304.

Of the original construction, a Greek cross with a hemispherical dome at the intersection of the arms, only the central body and part of the apse remain.

Over the centuries the Basilica has undergone numerous alterations, evidence of the various historical events that have followed one another and clearly visible in its multiform structure.

The first significant transformations took place when, in 1089, the Judge of Cagliari Costantino Salusio II de Lacon-Gunale gave it to the Vittorini monks of Marseille who restored it in typically proto-Romanesque forms, establishing the seat of the Sardinian priory of the Order.

After being damaged during the fourteenth century, it became, in the mid-fifteenth century, the property of the Archdiocese of Cagliari and, starting from 1614, the object of important excavations in search of the "holy bodies", ie the relics of the martyrs, which lead to the light numerous burials.

At the end of the same century the Basilica was partly dismantled to obtain material for the Baroque renovation of the Cathedral of Cagliari.

Severely damaged by the bombings of 1943, in the first post-war period the Basilica was affected by extensive reconstruction and restoration work, then rededicated and reopened for worship in 2004.