A Byzantine connection: Eastern Mediterranean glasses in medieval Bari

The transition from the Roman natron-based glass industry to the medieval ash-based tradition in Italy in the latter part of the first millennium CE is still poorly documented. The compositional data of eighteen glass fragments excavated from the Byzantine praetorium in Bari suggest that the development in the southern part of the Peninsula differs from that in the north. Analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) identified the first significant group of glasses in Italy that were produced in and imported from the eastern Mediterranean during the last two centuries of the first millennium CE. Some samples exhibit the characteristics of early Islamic natron and plant-ashglasses, while two specimens are similar in major and trace element composition to post-Roman glasses most likely manufactured in Byzantine Asia Minor. These represent the only known vessels made from the Byzantine high lithium, high boron glass found so far in the western Mediterranean. The analytical results thus show that being under Byzantine hegemony was advantageous for trade connections in the medieval Mediterranean.