The delicate medium of glass played an important role in the design of interior spaces in the Mediterranean world during the period stretching from the foundation of the Byzantine empire in the fourth century A.D. to the rise of Islam and the establishment of the first Muslim empires in the seventh and eighth centuries. The Museum’s collection contains a number of fragments of glass ornament excavated from late antique and early Islamic sites.
The most luxurious form of glass ornament in the late antique tradition was glass mosaic, or the creation of designs using thousands of tiny glass cubes called tesserae. The technique reached great heights in the Byzantine period (330–1453), when evidence of its use can be found at sites from Italy and North Africa to Mesopotamia and from major urban centers to rural monasteries. In the rebuilding of Constantinople’s Hagia Sophia completed in 537, for example, glass mosaics were used to cover the interior of the massive central dome as well as the vaulted ceilings along the side aisles and narthex. The mosaics visible today in Hagia Sophia represent several decorative campaigns and phases of renovation, but sections thought to date to the earliest period of construction in the sixth century are aniconic and include composite vegetal motifs and crosses in tesserae made of green, blue, and red glass, all set against a background of gold.
Glass mosaics in the Byzantine technique were valued far beyond the borders of Byzantium. After Sasanian emperor Khusrau I (r. 531–79) sacked the Byzantine city of Antioch in 540, he built a palace at Ctesiphon that included glass mosaics, evidence of which were unearthed through joint excavations undertaken at the site by the Met and the State Museums of Berlin ; . The mosaics may have depicted a scene from the Battle of Antioch itself, for the Arab poet al-Buhturi (died 897) describes an image of the battle preserved on a wall in this palace whose vibrant colors are reminiscent of mosaics. Buhturi specified that in this image, Khusrau was represented standing under a banner commanding ranks of troops. If Buhturi’s description is accurate, Khusrau’s use of glass mosaic may have been rhetorical: a celebration of Sasanian military victory executed in a medium associated with the rival power.
The first Muslim rulers who reigned from the formerly Byzantine and Sasanian territories of Syria, Iraq, and Egypt continued to exploit the aesthetic potential of the medium, and glass mosaics featured prominently in several major imperial monuments constructed by the Umayyad dynasty. The earliest surviving monument of Islam, the Umayyad Dome of the Rock in Jerusalem (691), included an extensive program of glass mosaics that covered the upper half of both its interior and exterior. Today, original seventh-century mosaics remain on the drum of the dome and on the spandrels and soffits of the two arcades surrounding it. In addition to a monumental Arabic inscription, they incorporate iconography from both Byzantine and Sasanian sources, including jeweled crowns and elaborate, composite vegetal motifs. At Damascus, the Umayyad caliph al-Walid I (r. 705–15) completed a congregational mosque that became world-renowned for its glass mosaics. The Damascus mosaics include clusters of pavilions and palaces set amid verdant landscapes, all against a brilliant golden background. Excavations at the ruins of the palace city of Samarra in Iraq (founded 836) revealed fragments of glass mosaic, demonstrating its continued use in ninth-century Mesopotamia .
The archaeological record points to the fact that, in addition to mosaic, glassmakers employed a variety of techniques to decorate architectural interiors. Some instances are surprising in their inventiveness. For example, excavations at the remote Kharga Oasis in Egypt’s Libyan Desert unearthed a domed funerary chapel that had been decorated with entire colored glass vessels impressed into the plaster of the ceiling. The excavators were able to collect a number of fragments of these vessels, now preserved in the Met .
Material excavated from Abbasid Samarra suggests that several different varieties of glass ornament featured in the decoration of its palaces. In addition to mosaic tesserae, finds included shaped inlay pieces made of clear mold-blown glass that appear to have been combined with mother-of-pearl pieces to form wall ornaments. Also notable among the Samarra finds are tiles made of multicolored glass rods, cut into cross-sections and fused to form repeating bull’s-eye patterns . These were likely employed on walls.
Early Islamic sites in Syria reveal yet another type of glass ornament. A glass tile in the Met is said to have been found in a church near the town of Ma‘arrat al-Nu‘man and has been dated to the early Islamic period . The tile is made of translucent purplish glass with a layer of gold leaf applied to its surface. Triangular sections were then cut out from gold leaf to form the shape of a cross, and a layer of transparent glass was applied on top. Placed together in a row, the tiles would have created a repeating pattern in purple set against a gold ground.
Although relatively few examples exist intact today, glass mosaics, glass tilework, and other forms of glass inlay formed part of decorative programs in the monuments of late antiquity and early Islam. Combined with other sumptuous materials such as wood, marble, and other decorative stones, these glass ornaments transformed the interiors of churches, mosques, palaces, and shrines.