coordinating the design of the tilework with the architecture of the buildings. Large quantities of tiles were required. In the 1550s and early 1560s the potters in Iznik made tiles for the Süleymaniye Mosque in Istanbul, the mausoleum of Hurrem Sultan (Roxelana) (completed in 1558), the Great Mosque in Adana (in around 1560), the Rüstem Pasha Mosque in Istanbul (completed in around 1563), and the mausoleum of Süleyman I (completed in 1567). The mausoleums of Süleyman I and that of his wife Hurrem Sultan are both located in the grounds of the Süleymaniye Mosque in Istanbul. Associated with this switch to tile production were important changes in the aesthetics. A bright red colour was introduced by the use of an iron containing bole applied as slip under the glaze. The red colour would become a common feature of Iznik tiles and pottery. The first building to have tiles with red was the Süleymaniye Mosque in Istanbul which was designed by the imperial architect Mimar Sinan and completed in 1557. The tile decoration inside the mosque is restricted to around the mihrab on the qibla wall. The repeating rectangular tiles have a stencil-like floral pattern on a white ground. The flowers are mainly blue but there is also turquoise, black and red. Outside the mosque on the north facade within the courtyard the windows have rectangular Iznik tile lunettes panels with text from the Quran. The white letters are written in thuluth script on a dark blue ground. The decoration on these tiles also includes the bole red. The next major monument designed by Sinan was the Rüstem Pasha Mosque which was completed in 1563. In contrast to the restrained use of tiles in the Süleymaniye Mosque, the surfaces in the interior and the façade under the portico at the entrance are all lavishly decorated with tiles. More than 80 different designs are used. Most of the tiles are in panels of repetitive patterns where each tile is identical to the others. The mosque is the first with the Kara Memi inspired red tulips and carnations. The mihrab is decorated with tiles painted with a thin brownish red but in other parts of the mosque there are tiles with the thick sealing-wax red relief. The purple used on 'Damascus ware' did not combine well the red bole and only a few monuments use both colours. Purple is used with red in