Tiles and earthenware followed a long trajectory of evolution in Anatolia. Tile slabs, which decorated the walls of buildings during the Seljuks, the time of Principalities and Ottoman era, attract attention with their variety of techniques and patterns. There is a paucity of earthenware that has survived from the Anatolian Seljuk era. However, with examples becoming more numerous with the advent of the 15th century, they represent the most popular pieces of private collections and local and foreign museums.

Tile decoration does not profusely feature in the structures remaining from the time of Principalities from the 14th-15th centuries. What little examples there are, they are like replicas of artefacts from the time of Seljuks, barely demonstrating anything original. In addition to tiles, glazed bricks also feature in the minarets of Birgi Grand Mosque (1312), Manisa Grand Mosque (1366-67) and İznik Green Mosque (1391-92). Tile mosaics, which were quite common during the era of Seljuks, had almost been forgotten during the time of Principalities and early Ottoman period. The tile mosaic decorations of this era, arranged in larger compositions compared to the Seljuk era, used blue, turquoise, purple and black colors in addition to white. The tile mosaic ornaments on the transitional elements of the mihrab of the Birgi Grand Mosque (1312) and the dome of the Selçuk İsa Bey Mosque (1375) date from the time of Principalities while those featuring in the İznik Green Mosque (139-92), Bursa Green Mosque, Green Madrasah and Green Tomb, as well as the Bursa Muradiye Mosque (1426) are rare examples from the early Ottoman period.

The decline in the use of tiles during the time of Principalities did not prevent the emergence of new techniques in the 15th century. The “colored glaze technique”, never seen before prior to this era, does not feature in Anatolian earthenware. The technique was exclusively applied to tiles. The tiles made using the colored glaze technique, which especially feature in the buildings of Bursa, Edirne and Istanbul, come in various colors such as blue, turquoise, dark blue, black, white, yellow, gold, violet, pistachio green, etc. The first examples of these tiles feature in the Bursa Green Mosque, the Green Tomb, Green Madrasah and the Edirne Muradiye Mosque (1426).

Konya, the center of tile production during the era of Seljuk, began to lose importance from the 15th century onwards, with İznik and Kütahya becoming the new centers of tile and earthenware. İznik, where the highest quality earthenware of the early Ottoman period were produced, has functioned as an important place of settlement since the 4th century BC. Its privileged location on the road that connects Istanbul with Anatolia has allowed the city to stay alive, economically and culturally. According to the accounts of travelers, there used to be about 300 tile masters in İznik. Although it sounds like an exaggeration for such a small town, the number of furnaces unearthed during recent excavations confirms this rumor.

Earthenware made using the underglaze technique, the so-called Miletian pieces, occupy an important place in the 14th and 15th century works of earthenware. It is understood that this earthenware with red ceramics body, given this name because it was believed that they had been made in Miletus until recently, used to be made in İznik. Ornaments with plant and geometric patterns also feature in this category of earthenware, which are usually either cobalt blue, dark purple or turquoise. For example, one often encounters compositions consisting of fan-shaped leaves drawn with thin brushstrokes, protruding from a central rosette.

This kind of earthenware, also called “blue-white”, appearing on the stage after the Miletian earthenware, had porcelain-like quality. These earthenware represent the second wave of innovation in the Ottoman era after the colored glaze technique. The underglaze technique, rarely featuring in tiles, often features in utility earthenware. This category of tiles and earthenware, manufactured in İznik until the beginning of the 16th century, featured the colors of blue, turquoise and dark blue on a white background. Peonies, flowers, Chinese clouds and dragons are the most prominent motifs of these tiles and earthenware, reminiscent of Ming porcelain from the Far East of the 15th century (“The Legacy of the Principalities, Early Ottoman Art”, pp.140-141).