CARNUNTUM. – A city of Upper Pannonia (Austria) in the Danube valley, an ancient road centre of great commercial and strategic importance for communications with the north. Already in the time of Tiberius and Claudius it had a fortified camp, seat of a legion (the XV and then the XIII), destroyed between 375 and 400; it had two amphitheatres: one, larger, in the city, the other, smaller, in the Castrum. Hadrian granted it the title of municipium Aelium, assigning it to the Sergian tribe. Septimius Severus transformed it into Colonia Septima.
Christianity in C. is attested by monumental remains, including a baptistery located at the southern entrance of the city’s amphitheatre, and by terracotta lamps, rings, engraved stones, medals bearing Christian symbols or formulas such as *in Deo vivas*, as well as by a bishop of the 4th century documented by a bronze votive plaque discovered in Rome near Ponte Sisto, now in the Museo Cristiano of the Pio Lateranense. This plaque formed part of a disc or crown (gabata) of gold or silver that the *gens Carnuntum*, as the inscribed epigram states, had offered through Mandronius, *venerando nomine*, to one of the Roman basilicas, probably the Vatican Basilica. The monogram of Christ { }_{2} \underline{\underline{b}} engraved in the small upper pediment, the style and palaeography of the epigram reveal the 4th century.