The glaze is less opaque on the other side: The development of Egyptian and southern Levantine glazed ceramic production from the early Islamic to Crusader periods

Our study seeks to explore the beginnings and spread of glazed ceramic technologies across Islamic lands by focusing on the evidence from the southern Levantine coast. We selected 98 glazed ceramic samples recovered through stratified excavations of four sites along the southern Levantine coast. These ceramic samples include glazed tableware (especially the ones that do not feature the use of opaque glaze) and cooking vessels that are representative of the range of ware types dating to the early Islamic and Crusader periods (9th to 13th centuries CE) in the region. All samples were subjected to technological reconstruction based on the data we generated using petrographic analyses and scanning electron microscopy energy dispersive spectrometry. A subset of 30 glazed ceramics were submitted for portable laser ablation (pLA) sampling for lead isotope analysis – making our study one of the first to test this sampling method on lead-based glazed materials. Our results show that the production and consumption habits of glazed ceramics was embedded in, and thus susceptible to, the broader historical developments. The vast majority of glazed ceramics dating to the early Islamic period (9th to 11th centuries CE) were imported from Egypt, which were made using pre-existing technologies. Our findings also highlight the importance of cross-craft and -cultural interactions, which serve to mark a departure from the traditional narrative on the beginnings and spread of glazed ceramic production across Islamic lands. We further noticed a greater presence of glazed ceramics that were produced along the Levantine coast, possibly in Beirut and/or northern Israel, from the end of the Islamic Fatimid caliphate to the Crusader periods (11th to 13th centuries CE), using technologies different from the Egyptian workshops. The results of our lead isotope analysis reveal that while the ores from Iran remain to be the main lead sources from the early Islamic to Crusader periods, the Egyptian and Levantine workshops also had access to different ore sources, namely in Tunisia and Sardinia, respectively, largely reliant on the exchange networks they were part of. • We explored how glaze technology began and evolved on the southern Levantine coast. • Most early Islamic glazed ceramics came from Egypt, using pre-existing technologies. • Crusader-period glazed ceramics were likely made locally, using different technology. • Early Islamic glaze technology was caused by cross-craft and -cultural interactions. • PLA-MC-ICP-MS reveals that Iranian ores were the main lead sources used through time.