The architecture of the Ottoman Empire, above all the domed mosques of the sixteenth century in which Sinan made the central dome, extended by semidomes and framed by pencil minarets, the image of Istanbul.
The Ottoman state began as a small principality in north-western Anatolia around 1300, and its early mosques at Bursa and Iznik are modest buildings of brick and stone covered by domes on squinches or Turkish triangles. The conquest of Constantinople in 1453 brought the Ottomans face to face with Hagia Sophia, the greatest domed building of the Christian world, which they converted into a mosque. For a century and a half the central problem of Ottoman architecture was how to rival it: how to cover a single great room for prayer with one dome, and how to make its exterior a composition worthy of an imperial city.
The first answers were the Fatih mosque (1463–70, later rebuilt) and the mosque of Bayezid II (1501–06), which borrowed Hagia Sophia’s two semidomes. They were followed by the career of Mimar Sinan, chief architect from 1538–39 until his death in 1588. Sinan explored every combination of central dome and supporting elements: four semidomes at the Şehzade (1543–48), two at the Süleymaniye (1550–57), a dome on a hexagon or an octagon of piers in smaller mosques, and finally, at the Selimiye in Edirne (1568–75), a dome of about 31 metres on eight slender piers, enclosing a space more unified than Hagia Sophia’s.
The exterior of a Sinan mosque shows its structure: from the central dome, ringed with windows, the load descends through semidomes, exedrae, corner domes and buttresses, with weight towers over the piers, in a cascade of lead-covered forms. In front lies a forecourt (avlu) surrounded by a domed portico, with an ablution fountain at its centre, and at the corners stand slender minarets with one to three balconies, their number marking the rank of the founder. The mosque itself stands at the centre of a complex (külliye) of schools, hospital, soup kitchen, baths, shops and tombs, a piece of city built for charity.
Inside, the walls are white or softly painted, and colour is concentrated in panels of Iznik tile (the tomato-red, cobalt and turquoise tulips and carnations of the Rüstem Pasha mosque) and in stained-glass windows. After Sinan, his pupils built the Sultan Ahmed Mosque (1609–16), with six minarets, and in the eighteenth century Ottoman architects absorbed European Baroque ornament, but the classical formula of the sixteenth century remained the model for mosques across the Balkans and the Middle East into modern times.