A Tale of Two Legacies: Byzantine and Egyptian Influences in the Manufacture and Supply of Glass Tesserae under the Umayyad Caliphate (661–750 AD)

Abstract

The connection between Umayyad and Byzantine mosaic manufacture is a debated issue: on the one hand, Arab sources report that Umayyad caliphs received craftspeople and materials to adorn religious buildings from the Byzantine emperor; on the other hand, the reliability of these texts has long been disputed among scholars, and other possible influences have been hypothesised. Was early Islamic mosaic manufacture related to Byzantine tradition and to what extent? Were materials and artisans gathered from Byzantium and/or territories under the Byzantine control? Based on a multi-analytical approach, glass tesserae from Khirbat al-Mafjar, the Great Mosque of Damascus, and the Dome of the Rock have been analysed. Results speak of a tale of two legacies, demonstrating that, parallel to a continuity with the manufacture of glass tesserae in the late antique Levant—pointing, more specifically, to a re-use of materials from abandoned buildings—legacies other than Byzantine occurred. It emerged that Egypt definitively played a role in mosaic making during the Umayyad caliphate, acting as a supplier of skilled artisans and materials.

The Persistence of Memory. Exploring the Significance of Glass from Materiality to Intangible Values

“…As a chrono-typological study is unfeasible for this category of object, color and opacity are the only features that can be used to define chromatic coordinates in an objective way, and to support a scientific-based selection among the copious assemblages of samples to be analyzed. As more extensively discussed elsewhere [35,36], a combined standard color system chart (such as NCS Index or PANTONE) and visible reflectance spectroscopy (VIS-RS) approach can be used to support an objective definition of the chromatic hues and shades of deeply colored glass, thereby avoiding any subjective nomenclature.…”

Once upon a Glass—Cycles, Recycles and Reuses of a Never-Ending Material

“…Recent studies attest to the reuse of tesserae "taken" from pre-existing monuments in the making of the mosaic decorations of the monuments of Syria's first Islamic Caliphate, a practice described by textual sources and partly confirmed by archaeometric analyses. Compositional analyses revealed the presence of both Levantine and Egyptian compositional categories: Apollonia-type and Foy-2 base glass indicate a continuity with the production of mosaic glass tesserae in the late antique Levant; Egypt I glass clearly distinguishes Umayyad tesserae, providing tangible evidence of other legacies [63]. A recent study on a prominent assemblage of glass tesserae from the Great Mosque of Damascus has further demonstrated Egyptian glass's dominance among the coloured tesserae, with other base glass types in circulation prior to the 8th century [64].…”

“…It is difficult to say whether these tesserae were simply reused or if the glass was recycled and transformed into tesserae during construction. Parallels can be drawn with 8th-century glass vessels, where there is a significant decline in Apollonia-type Levantine I, while Foy 2.1 is missing; it appears more likely that the tesserae represent reused material collected from older mosaics or some storage facilities [63]. Al-Maqdisī, al-Ya'q ūbī, ibn Zabāla, al-Dinawārī and ibn Rusta report mosaic cubes sent from the Byzantine emperor to Umayyad caliphs, and al-Tabarī also states that the emperor ordered searches for these cubes in ruined cities [63,65].…”

“…Parallels can be drawn with 8th-century glass vessels, where there is a significant decline in Apollonia-type Levantine I, while Foy 2.1 is missing; it appears more likely that the tesserae represent reused material collected from older mosaics or some storage facilities [63]. Al-Maqdisī, al-Ya'q ūbī, ibn Zabāla, al-Dinawārī and ibn Rusta report mosaic cubes sent from the Byzantine emperor to Umayyad caliphs, and al-Tabarī also states that the emperor ordered searches for these cubes in ruined cities [63,65]. It should also be noted that the rise of the Umayyad caliphate occurred during a period when the production of mosaics appears to have declined significantly in the Mediterranean basin: between the 7th and 8th centuries, when the number of new buildings adorned with mosaics dropped from more than 50 to 20 and then 9 exemplars [66].…”