The history of glass and glasswork is as old as that of civilization. Glass was introduced into Islamic architecture first as the stained glass windows called revzen and was widely used in daily ware such as oil lamps, decanters, mugs, and plates. Glasswork reached its zenith about the end of the 12th century during Mamluk and Ayyubid periods. In the Seljuk and Artukid periods, the glassware with bulge, called şemsiye (umbrella), were produced. The developed state of Seljuk glasswork is attested from the few extant examples. The excavations at the Kubadabad Palace on the western coast of Beyşehir Lake, Konya, yielded bulging or round window glass fragments in blue, green, brown, purple and yellow colors, colored goblets, bottles and plates. These examples revealed that Seljuks produced glasswork both by hand and on the wheel; and decorated them by carving, cutting and burnishing. During the Ottoman period, the glasswork improved greatly with the development of new styles. The glassworkers’ guild was established under the Imperial Guards. The Ottoman glassworkers called camgeran had a very strong occupational organization and had masters titled nazır (superintendent), kethüda (warden), nakib (chief), çavuş (guard), yiğitbaşı (head of apprentices and disciples), duacı (one who prays) and workshop owners. All these officials checked the quality of production and the prices, and the products that did not abide by the quality regulations were broken by the nazır and the producer masters were punished. The small merchants that sold or mounted glass on the buildings were directly under the control of the head architect. Glass workshops clustered around Tekfur Palace. Around the Baruthane-i Amire in Bakırköy were the burnishing workshops, glass factories, saltpeter cauldrons and kilns. During the Rhodes campaign of Süleyman the Magnificent, the Ottomans used glass bombshells. In the Surname, a renowned illuminated manuscript depicting the circumcision festival of Prince Mehmet, son of Murad III, the glassworkers’ guild is depicted amongst the guilds parading before the sultan in Sultanahmet Square. The stained glass widely used in Turkish architecture, e.g. Topkapı Palace, Süleymaniye, Mihrimah, Rüstem Pasha and Sultan Ahmet Mosques, is of significance from the point of plasterwork and glasswork. In the 18th century, a whirling dervish called Mehmet Dede went to Italy and worked in glasswork ateliers; on his return he established his own workshop in Beykoz, Istanbul, and produced the Beykozware- the crystal bowls, plates, mugs, bottles, tulip vases and rosewater flasks that change into red color when held to light. On the order of Sultan Abdülmecid he founded a large workshop at Paşabahçe in 1848. In Çubuklu, the glassware called çeşm-i bülbül, which are produced by firing in kilns the alternating sticks of glass and ceramic for a long time at a low temperature. With their large bands, Turkish style forms and peculiar aspects the Turkish çeşm-i bülbüls distinguish themselves from their European counterparts.