In the latter half of the fifteenth century, following the Fall of Constantinople and the establishment of the Ottoman Court in the former capital of the Byzantine Empire, many areas of artistic production enjoyed a renewal of forms. These changes reflected the fuller involvement of a court whose patronage was particularly evident in book arts and in the textile industry. This courtly demand also seems to have given rise towards the end of the reign of Mehmet II to the production of ceramic wares of great technical perfection, designed for a new elite eager for luxury objects. This production of high-quality ceramics was to endure in the sixteenth century, before the onset of a period of progressive decline throughout the seventeenth century.
These high-quality ceramic wares, referred to as çini in Ottoman documents, were intended for the domestic market of the Ottoman Empire, but were also soon exported outside of the Empire, to Italy in particular, where the exported wares would give rise to local imitations. Though Iznik was the main centre of production, such ceramic wares were also produced in the city of Kütahya, as is borne out by finds from excavations carried out there. Istanbul may also have been the site of sporadic productions directly linked to commissions from the court.
These new Iznik ceramic wares had a stonepaste body, whose plumbiferous nature and high percentage of frit (a vitreous substance) set them apart from earlier stonepaste pottery produced in the Islamic world. According to the latest analyses, the composition of the stonepaste of Iznik ceramics was as follows: 65 to 75 % quartz; 15 to 18% frit rich in lead and lime; 3 to 4 % highly plumbiferous frit; only 8 to 13 % non-calcareous clay with a low proportion of iron oxide that was to impart a slightly pinkish hue to the body once fired. The addition of frit, obtained from crushed glass, was indispensable here, as when molten it would form a binder between the quartz particles. The low clay content of stonepaste reduced its malleability, making it difficult to turn; certain forms such as dishes with everted flanges or chargers were therefore obtained with the help of a template placed on the wheel and an exterior mold.
The body was then coated with a slip – thinned siliceous clay – similar in composition to the paste and providing a perfect “fit” to the body. The decoration was applied to this slip coating when dry or perhaps after an initial firing of the body. It was trailed using a brush and various pigments and coated with a colorless glaze. While designs could be traced freehand, the highly structured compositions of many Iznik wares required the use of stencils. Many existing objects testify to their use, such as twin pieces and pieces with designs made up of identical motifs repeated at regular intervals, or “repeating-module tiles” used to form entire wall panels.
The composition of the tin-opacified lead-alkali glaze which coated the decoration was another distinctive feature of Iznik ceramics. This vitreous substance was of a highly pure composition here, characterized by a very low potash and magnesia content; these residual elements traditionally found in lead-alkali glazes came from their alkaline flux that was obtained from the ashes of plants from coastal or desert regions. The virtually total absence of such residue may be due to an additional ash purification stage, a technique used to produce Venetian cristallo glass from the mid-fifteenth century onward and which may have come to the notice of Iznik potters. The extremely transparent glazes of Iznik ceramic wares nonetheless contained a small proportion of tin. Firing temperatures for Iznik ceramics can only be estimated; such estimations range from 850-900° C to 1200° C.
The golden age of Iznik ceramic wares covered the whole of the sixteenth century, undergoing much formal evolution and enjoying increasing diversification of its decorative repertoire, with decline setting in from the early seventeenth century onward. Despite the lack of dated items, art historians have managed to piece together a relative chronology of the evolution of Iznik ceramics, bringing out the stylistic phases and delimiting the emergence of certain forms.
Iznik tile production started to boom around the mid-sixteenth century and was stimulated and controlled by court commissions. Iznik was the main production center of underglaze painted tiles, but the city of Kütahya was to flourish throughout the seventeenth century. Many archival documents testify to the link between Iznik workshops and the court, including complaints addressed to the kadi of Iznik on delays in delivery or the misappropriation of tiles sold to merchants instead of being sent to the capital.
Ceramicists working in Istanbul appear to have played an important role before the mid-sixteenth century. Archive documents testify to the existence of a certain number of kasigeran (tilemakers) at that time among the craftsmen directly attached to the court (ehl-i hiref), whereas their number would become insignificant in the second half of the century.
These craftsmen produced both underglaze painted and cuerda seca tiles. The technique of cuerda seca, which appeared towards the late fourteenth century in Central Asia, had already been used in the fifteenth century in monuments of early Ottoman art, through the intervention of craftsmen who had been trained in this technique at the Timurid court. It enjoyed renewed favor shortly after Selim I captured Tabriz, once again impelled by craftsmen of Iranian extraction. These cuerda seca designs are attributed to a group overseen by a certain Habib of Tabriz, then by his successor Usta Ali, both mentioned in the archives of the Topkapi Palace. This technique, which is to be found on several buildings in Istanbul, attained the height of its perfection with the interior decoration of the tomb of the Sehzade Mehmet (1445-48). Shortly after this mausoleum decoration was produced, this technique went out of fashion, to be supplanted by underglaze painted designs. The Dome of the Rock in Jerusalem was the last large building project to feature it.
In Istanbul, the same group of ceramicists may have produced underglaze painted tiles intended to decorate pavilions built in the Topkapi Palace. Some of them bear some relation to the decoration of cuerda seca tilework; in particular, they share a repertoire of motifs that appear to be executed in the stencil style. The most remarkable achievements that can be attributed to these workshops are two monumental plaques reused in the seventeenth century on the façade of the Sünnet Odasi (Circumcision Room) featuring a saz landscape peopled with fabulous beasts. The perfection of the drawing is probably due to the intervention of a designer from the imperial nakkashane – perhaps Sahkulu himself. The coloring is still limited here to cobalt blue and turquoise, and matches that of contemporaneous Iznik ceramic wares.
From the early sixteenth century onward Iznik craftsmen would also have produced tiles, sporadically and still on a very limited scale. The tiles of the mausoleum of Sehzade Mahmud (around 1506), very close to the style of Baba Nakkas pottery wares, are one example attesting to this output. In the latter half of the sixteenth century, when commissions for underglaze painted tiles came flooding into Iznik workshops, their designs and color schemes evolved in accordance with those of ceramic vessels. One part of the repertoire was firmly rooted in the tradition of architectural tilework, with "stencil-style" motifs, while elements characteristic of the saz and sukufe registers found on vessels were also in evidence. Red was first seen in the tilework decoration of the Süleymaniye (completed in 1559) and provides a benchmark for dating vessels bearing this color. Then was to begin a golden age with a succession of large building initiatives that gave rise to unique decorative programs in which tilework would match painted work (kalem isi) or exterior designs carved in stone: the Rüstem Pasa Mosque (circa 1561), the Sokollu Mehmed Pasa Mosque (1572), or the mausoleums of Roxelane (1558), Süleyman the Magnificent (1566), or Selim II (1572).
These ceramic designs, like the Ottoman architectural style that came to assert itself in these provincial towns, are all echoes of the evolution of forms and tastes that spread from the capital of the Empire to the provinces. Craftsmen from Iznik would execute the decorations of the monuments of Antalya, Aleppo, or Diyarbakir locally. The color palette characteristic of Iznik wares recurs here, yet with slight differences: a less rigorous symmetry, a more irregular grid, different standards of sizes, and a glaze of lesser quality.
In the city of Damascus, a more original production, nonetheless influenced by the decorative repertoire of Iznik tiles, came into being shortly after the renovation of the Dome of the Rock. Some of the craftsmen who worked on the restoration of this prestigious monument may then have gone on to settle in Damascus, where they made the tiles destined for the pious foundations constructed in this city by Süleyman the Magnificent or high-ranking Ottoman dignitaries. One of the first constructions was the mosque of Süleyman the Magnificent built around 1550-54. It revealed for the first time tilework inspired by Istanbul creations but in a color palette that was subsequently to mark Damascene production: turquoise blue, chrome green, and aubergine brown. The Damascene color palette – which is also that of Iznik wares from the 1540s and 1550s – is a color scheme that was already found in the Mamluke era. However the craftsmen of Damascus also maintained the taste for designs trailed in black beneath a turquoise glaze – a further legacy from the medieval past adapted to a specifically Ottoman decorative repertoire. The local production of tiles – known in Damascus by the term qishani, derived from the name of the Iranian city of Kashan – seems to have endured since the Mamluke era. The stonepaste was also made according to recipes dating back to medieval times, and the glazes remained mainly alkaline and subject to crackling.