ORIGINAL PAPER An archaeological and chemical investigation of 11th–12th centuries AD glasses from Zeyrek Camii (the Pantokrator church) in Byzantine Constantinople Ieong Siu 1 & Julian Henderson 1 & Üzlifat Canav-Özgümüş 2 & Andrew G. Tindle 3 Received: 23 January 2018 /Accepted: 3 September 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Fifteen glass window, vessel and glass chunk samples collected from the western part and substructure of Zeyrek Camii (the Pantokrator Church) in Istanbul were analysed using an electron microprobe (EPMA). The results show that these samples are all soda-lime-silica glass. Based on the major and minor elements, two different compositional groups were identified and evidence of recycling/mixing was also revealed. Group 1 is plant ash-based glass, while group 2 is the result of mixing natron and plant ash glasses. Comparison with contemporary glass objects from the eastern Mediterranean shows that these glasses probably derived from at least two different production zones in the Syro-Palestinian region: (1) possibly Damascus or Banias and (2) possibly Tyre. The authors suggest that the trading of plant ash glasses between the Byzantine Empire and the Middle East in the 11th– 12th centuries AD was well established based on the archaeological and scientific evidence. Keywords Byzantine glass . Plant ash glass . Recycling . Electron microprobe . Zeyrek Camii Introduction Traditionally, ancient glass is studied using typological and art-historical approaches using decorative styles. These ap- proaches can help us to investigate the evolution of the glass vessel forms across space and time, to some extent, and the provenance of the glass vessels. More recently, chemical analysis of glass has been proven beneficial to investigate the technology of glassmaking including raw material use, glass provenance, glass distribution patterns and trade. A combination of archaeological, typological and chemical studies of glass can help us to investigate the technological, social and economic aspects of ancient glass. This study attempts to apply these approaches to the study of glass from middle Byzantine (11th–12th centuries AD) Turkey. A limited number of investigations of middle Byzantine glass has been carried out using combined archaeological, typological and chemical approaches. Previously, many schol- arly discussions and debates on middle Byzantine glass centred on luxury glasses, such as the painted and enamelled glasses from the Treasury of San Marco and vessels in the British Museum (Henderson and Mundell Mango 1995; Ristovska 2009; Tait 1995). More recently, researchers have begun to use a combined archaeological and scientific ap- proach to study Byzantine glass such as that from Hosios Loukas, Dalphni, Amorium, Pergamon, Nafaru, Zeyrek Camii and Kariye Camii, and glass from the eleventh century AD shipwreck Serçe Limani, in order to understand the tech- nological and economic aspects of middle Byzantine glass (Arletti et al. 2010; Brill 2005, 2009; Brill and Stapleton 2012; Bugoi et al. 2013; Schibille 2011; Wypyski 2005). However, such researches are relatively few and they some- times only focus on the technological aspects of Byzantine glass. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12520-018-0700-0) contains supplementary material, which is available to authorized users. * Ieong Siu alex329as@hotmail.com 1 Department of Archaeology, The University of Nottingham, University Park, Nottingham NG7 2RD, UK 2 Department of Ceramic and Glass, Vocational School of Technical Sciences, Istanbul University, Ulus Mah. Kültür cad. No:9 34537 Büyükçekmece, Istanbul, Turkey 3 School of Environment, Earth and Ecosystem Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK Archaeological and Anthropological Sciences https://doi.org/10.1007/s12520-018-0700-0