There are two niches in the mosque, with often overlooked but marvellous tiles in their ceiling. There is a bit of glare that I could not prevent.

The Yeşil Cami (‘Green’ mosque, because of the predominant colour of its tiles inside) is the most decorated of the city’s houses of prayer. Built for sultan Mehmed I Çelebi (1389-1421) by the architect Hacı Ivaz Paşa, who was also an army commander and a vizier; he is the architect of the Yeşil Türbe (mausoleum) too. The mosque’s building was completed in 1419, its inner decoration in 1424.
The Yeşil Mosque can be shown as the perfect blend between architecture and embellishment, the proof that such works of art were produced in a country where the battles between siblings had come to an end and peace had returned.

On the picture: Generally the ceilings in mosques are not tiled like the walls, but painted. Not here, however, in this small room next to the vestibule. These tiles were locally produced, by artisans from Tabriz (Iran), under the supervision of Ali bin İlyas Ali, a ‘nakkaş’ (painter-designer) from Bursa, who had been sent to Samarkand by Timurlenk in 1402. Most tiles were made using the so-called ‘cuerda seca’ technique, followed by ingenious gilding patterns.

Cuerda seca: A brilliant but short lived episode in the history of Anatolian ceramic production was the appearance of tiles decorated in the ‘cuerda seca’ (="dry cord") technique. In the ‘cuerda seca’ process, thin bands of waxy resist maintain color separation between glazes during firing, but leave behind "dry cords" of unglazed tile. This technique seems to have been introduced to Turkey from Iran as early as the fourteenth century. These tiles are often distinguished by their curving shape. (Source: The Metropolitan Museum of Art, New York) .

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Türkye Tarihi Yerler Kılavuzu’ – M.Orhan Bayrak, Inkılâp Kitabevi, Istanbul, 1994 - Wikipedia,
& ‘Vakıf Abideler ve eski Eserler’ - Vakıflar Genel Müdürlüğü III, Ankara 1983 .