Bowl with Knotted Dragons 12th century This bowl shows an aspect of ceramics produced in twelfth-century Syria and the Jazira that proved unappealing to early twentieth-century collectors. While the painted design is exquisite, the whitening of the alkaline glaze when it was buried rendered the imagery almost illegible. This ware represents a large proportion of the glazed ceramics of the period found in excavations, but restorers have not found a way to enhance the pieces successfully, and they are underrepresented in collections.. Bowl with Knotted Dragons. 12th century. Stonepaste; underglaze-painted, transparent turquoise glaze. Attributed to Syria, Raqqa. Ceramics