Crossing the art/science disciplinary boundaries, Professor Liz James and an international group of archaeologists, art historians and glass scientists are re-evaluating the technology behind the construction of Byzantine mosaics and the composition of Byzantine glass mosaic tesserae.
Mosaic from the Rotunda of St George in Thessaloniki, 5th-6th century
When one thinks of Byzantine art, the picture most likely to come to mind is of mosaics – beautifully coloured, richly detailed images, primarily depicting religious iconography, from an empire that spanned over a thousand years. Over the last three years, an international, multidisciplinary group of scholars, sponsored by the Leverhulme Trust, has been involved in the study of the composition of Byzantine glass to understand better the origins of these mosaics.
When studying other periods of art history, such as the Renaissance, in addition to the art itself, there is a wealth of knowledge about the artists who created it and detail of how it was produced. In contrast, for those who study Byzantine art, other than the physical presence of the mosaics on the walls, there is little or no surviving information on how they were made or who made them.
Byzantine mosaics are composed of thousands, or tens of thousands, of tiny pieces of coloured glass tesserae and, to a greater or lesser degree depending on the mosaic, similarly shaped pieces of differently coloured stone. Through the study of these tiny pieces of glass tesserae, one can begin to formulate and answer questions about their provenance and production, possible consumer sites, and patterns of trade in the glass, which in turn might increase understanding of the wider economic and cultural connections in the Byzantine world. To begin to address some of these issues, Liz James, Professor of Art History at the University of Sussex, has been involved in workshop projects designed to foster collaboration between an international group of art historians, archaeologists and glass scientists with specialist interests in Byzantine art and history and in glass technology.
By bringing together the disciplines of art and science, one can begin to ask new and different questions that unpick previous assumptions about how mosaics are understood to have been made. One such assumption, when thinking about mosaics from a purely artistic perspective, might be that the style and appearance of a piece is attributable to the preference of the artist. However, thinking about the composition in more technical terms changes the questions that might be asked. For example, how much of the style of a particular mosaic is dictated by the materials and technology at the artist’s disposal rather than artistic preference? In early Byzantine art, does the prevalence of green glass tesserae at sites across the Mediterranean and Near East indicate the existence of a widespread industry in producing this colour of glass? Do the comparative rarity and the difficulty involved in making red glass indicate that there were only a few specialised sites hosting that particular technology? Similarly, are the shifting colour palettes observed across time – from a proliferation of greens and blues in the 5th, 6th and 7th centuries to more gold, pinks and browns being used in the later Byzantine Empire – because of technological, cultural or artistic factors? Did the switch from the use of reflective white and pink glass in the faces of 6th-century religious icons to the use of matt stone in the 11th century demonstrate changing artistic choices, or the loss or discarding of a specific technology?
By studying the composition of the glass tesserae – where it comes from, how it was coloured, where in its lifecycle it was coloured – it may be possible to begin to answer some of these questions. The project, which involves scholars from Sussex, the Universities of Cardiff, Nottingham, Thessaly and Bologna, from Lyons and Venice, and from the Department of Antiquities in Israel, as well as museums such as the Benaki Museum in Athens, the British Museum in London and the Metropolitan Museum in New York, has been designed to facilitate discussions that will shed new light on the origins of Byzantine art.
Extracted from the 2011 Research Review.