of Sextus Pompeius, Caralis was the only city which offered any resistance, but was taken after a short siege.
Cagliari continued to be regarded as the capital of the island under the Roman Empire, and though it did not become a colony, its inhabitants obtained the rights of Roman citizens.
A Christian community is attested in Cagliari at least as early as the 3rd century, and by the end of the century the city had a Christian bishop. In the middle decades of the 4th century the bishop Lucifer of Cagliari developed the so-called Luciferian heresy. He was banished to the desert of Thebais by the emperor Constantius.
After the fall of the Western Empire Cagliari fell, together with the rest of Sardinia, into the hands of the Vandals, but appears to have retained its importance throughout the Middle Ages.
Claudian describes the ancient city as extending to a considerable length towards the promontory or headland, the projection of which sheltered its port: the latter affords good anchorage for large vessels; but besides this, which is only a well-sheltered road-stead, there is adjoining the city a large salt-water lake, or lagoon, called the Stagno di Cagliari, communicating by a narrow channel with the bay, which appears from Claudian to have been used in ancient times as an inner harbor or basin. The promontory adjoining the city is evidently that noticed by Ptolemy (Κάραλις πόλις καὶ ἄκρα), but the Caralitanum Promontorium of Pliny can be no other than the headland, now called Capo Carbonara, which forms the eastern boundary of the Gulf of Cagliari, and the southeast point of the whole island. Immediately off it lay the little island of Ficaria, now called the Isola dei Cavoli.
Giudicato of Cagliari
Subsequently ruled in turn by the Vandals and the Byzantine Empire, Cagliari became the eponymous capital of an independent kingdom or giudicato, ruled by a giudice or judike (literally
