Hagia Sophia

Hagia Sophia, ”Church of the Holy Wisdom”, great basilica, completed in 537, that served as the cathedral of Constantinople (now İstanbul) and the spiritual heart of Eastern Christianity until the final extinction of Byzantium in 1453. It is also regarded as the greatest monument of Byzantine architecture.

The first Hagia Sophia was a typical Roman basilica, timber-roofed and entered through an atrium. It was virtually destroyed by fire in 532. The emperor Justinian I immediately ordered the construction of the present building, which was substantially complete by 537, when it was dedicated, although work continued until 563. The architects, Anthemios of Tralles and Isidorus of Miletus, designed the new cathedral as a huge, almost square interior surmounted by a vast central dome. The dome, which rises some 56 m (185 ft) from ground level, appears to be dramatically poised over a circle of light radiating from the windows that pierce the drum on which it rests. Four curved triangles, or pendentives, support the rim and are in turn locked into the corners of a square formed by four huge arches. The transition between the circular dome and the square base of the building, achieved through the use of the pendentives, was a major advance in building technology. To the east a vast semi-dome surmounts the three large vaulted niches of the sanctuary below. Arcades that recall the arcaded naves of basilica churches occupy the ground level on the northern and southern sides of the central square. To the west, another huge semi-dome precedes a barrel-vaulted narthex (antechamber).

Hagia Sophia became a great centre of pilgrimage and was elaborately decorated with mosaics and rich furnishings. The most important of the mosaics were installed during the 9th century, after the depredations of the Iconoclasts, though work continued into the 14th century.

Hagia Sophia was plundered by the Crusaders in 1204 and converted into a Catholic cathedral. It reverted to Orthodox use in 1261 but Christian worship ceased forever when Constantinople fell to the Ottoman Turks under Mehmed II in 1453. The building was turned into a mosque and minarets were subsequently added. The interior was whitewashed. The building was, however, well maintained and in 1847-1848 a thorough restoration was carried out, the mosaic decorations being uncovered (but masked by large plaques) and the structure consolidated.

Hagia Sophia continued in use as a mosque until the 1930s, when it was secularized by the Turkish state. It opened as a museum in 1935 and further restoration work to the interior has since taken place. In 1985, along with other historic areas of İstanbul, Hagia Sophia was designated a UNESCO World Heritage Site.