period are believed to be influenced by Ottoman metalwork. Although both the use of cobalt blue on a white background and the shape of large dishes were clearly influenced by Chinese porcelain from the Yuan and Ming dynasties, the early Iznik fritware dishes were far from being direct copies of Chinese designs. In some pieces, such as the front of a large charger with a foliate rim in the Çinili Koşk Museum in Istanbul, the decoration used only Ottoman Rumi designs. During the first two decades of the 16th century there was a gradual shift in style with the introduction of a brighter blue, more use of a white background and a greater use of floral motifs. Dating from this period are four mosque lamps from the mausoleum of Sultan Bayezid II in Istanbul which was constructed in 1512–13. A fifth lamp that probably also came from the mausoleum is now in the British Museum. These pottery mosque lamps are of a similar shape to Mamluk glass lamps. There was a tradition of hanging pottery lamps in mosques dating back at least to the 13th century. The opaque pottery lamps would have been completely useless for lighting and they instead served a symbolic and decorative function. The lamps from Bayezid II's mausoleum are decorated with bands of geometric motifs and kufic inscriptions but around the centre they have a very prominent broad band containing large rosettes and stylized lotus blossoms. Patronage by the Ottoman court: Süleyman the Magnificent After the conquest of Constantinople in 1453, the Ottoman sultans started a huge building programme. In these buildings, especially those commissioned by Süleyman, his wife Hürrem (Roxelana) and his Grand Vizier Rüstem Pasha, large quantities of tiles were used. The Sultan Ahmed Mosque in Istanbul (the "Blue Mosque") alone contains 20,000 tiles. The Rüstem Pasha Mosque is more densely tiled and tiles were used extensively in the Topkapı Palace. As a result of this demand, tiles dominated the output of the Iznik potteries. Under Süleyman the Magnificent (1520–66), demand for Iznik wares increased. Jugs, hanging lamps, cups, bowls and dishes were produced, inspired by metalwork and illuminated books as well as Chinese ceramics. Many large dishes were made with looser designs, incorporating ships, animals, trees and flowers. The dishes appear to have been made for display, as most have pierced footrings so that they can be hung up, but they have been