With the fall of the Western Roman Empire, conventionally dated in 476 A.D., Sulky, like the rest of Sardinia, came under the rule of the Vandals. The Vandals were populations of Germanic origin who settled in North Africa; they stayed in Sant'Antioco for about eighty years. During the fifth century A.D. there is proof of the coexistence between a Christian and a Jewish community in Sulky, the latter attested at least since the second century A.D. Both these communities reused the Punic underground tombs as family graves, during the same period and in the same sector of the city suburbs (figs. 1-2).

Fig. 1 - Decoration of a Jewish Arcosolium (from BARTOLONI 1989, fig. 44).

Fig. 2 - All that remains of the representation of the Good Shepherd in the lunette of arcosolium C, at the end of corridor B (in TARAMELLI 1921, p. 149, fig. 5).

Some tombs of the ancient Punic necropolis were in fact reused: they were connected via openings made by breaking through the original walls of the chambers and therefore creating the cemetery known as the Catacombs of S. Antioco; next to it, the cemetery of Santa Rosa, less extensive (fig. 3). The so-called "altar of the Saint" was added inside the cemetery (fig. 4).

Fig. 3 - Plan of the Catacombs of Sant'Antioco and Santa Rosa (in TARAMELLI 1921, p. 145 fig. 1).

Fig. 4 - Altar-sarcophagus of Sant'Antioco inside the catacombs with the same name (in BARTOLONI 1989, fig. 45).

The building which exists today, dedicated to the saint, is not that of the fifth century B.C., but a building whose origin does not date back beyond the Byzantine period (VI-X century A.D.) and which underwent extensions and transformations during the centuries (fig. 5).

Fig. 5 - The present church of Sant 'Antioco, whose current façade dates back to the eighteenth century (from http://www.diocesidiiglesias.it/iglesias/allegati/22878/basilica%20grande.jpg).

The Byzantine Age officially started in 534 A.D., following the victory of General Belisario at Tricamari near Carthage (therefore in today’s Tunisia) against the Vandals. From that moment, Sardinia became part of the Eastern Roman Empire and became, along with Corsica and the Balearic Islands, one of the seven provinces of Byzantine Africa constituted by Emperor Justinian (fig. 6).

Fig. 6 - The Byzantine Empire at the time of Justinian (from http://www.ilcasalediemma.it/writable/allegati/giustiniano+espansione1580.jpg).

During the previous Vandal period, the Christian communities in Sardinia were able to organise to their best advantage. Sulky was an episcopal see at least since 484, as it had attended the Council of Carthage with its Bishop Vitale.

During the early Middle Ages, the topography in the southern suburbs of Sulky was characterised by a monumental complex of some importance, called castrum sulcitanum, of which nothing remains today, but of which we still have the useful descriptions by Vittorio Angius, Alberto della Marmora, Canon Giovanni Spano and later Dionigi Scano.

At the beginning of the eighth century Sardinia began to be targeted by the Arabs and the island of Sant'Antioco was one of the main objectives of their raids. The first time this happened, the people of Sulky were unprepared and put up no resistance; the Arabs were free to plunder and to take captives. After that the invasions became recurrent and they forced the inhabitants to seek refuge inland, leaving the island of Sant'Antioco virtually abandoned until the tenth century. The Saracen raids resumed during the first half of this century and it is in this period that the figure of the Giudici as governors of Sardinia appeared. A substantial autonomy of the island began being asserted, and the island was divided into four Giudicati for a better administration management: Cagliari, Arborea, Torres and Gallura (fig. 7).

Fig. 7 - The division of Sardinia into Giudicati, around the tenth century (from http://sito24.com/templates/template.php?tipo=I%20Giudicati%20Sardi&nome=storica&siteid=24676).

Sant'Antioco was part of the Giudicato of Cagliari. In the year 1089 it was the Giudice of Cagliari, Constantine, who granted the Vittorini monks the sanctuary of Sulcis together with its entire surroundings. The monks restored the church which had partially been destroyed by the raids, giving it new life in 1102. Only in the eighteenth century, during the Savoy period, did the process of repopulation of the area begin, giving birth to the modern town of Sant'Antioco which overlaid the ruins of the ancient Sulky. The poorest part of the population occupied part of the Punic necropolis, exploiting the underground graves as dwellings, adapting them to basic housing needs (fig. 8).

Fig. 8 - Reconstruction in situ of one of the Punic underground tombs in Sulky reused as dwelling in the eighteenth century (photo by M. Murgia).