The church of Hagia Sophia (Holy Wisdom in Greek) was commissioned by the Byzantine emperor Justinian I (527–565) and built by the mathematicians Anthemius of Tralles and Isidore of Miletus. The church was inaugurated in 562 after more than five years of labor by over 10,000 workers. It replaced an earlier structure, the Great Church, which was destroyed by fire in the Nika rebellions of 532. The destroyed building was a conventional timber-roofed basilica. In replacing it Justinian and his architects combined elements from basilican—and centrally—planned structures to create a new architectural plan most frequently characterized as a domed basilica. The individual elements used in the building were not new; it was rather their combination that was innovative. Hagia Sophia was originally fronted to the west by a porticoed atrium with a central fountain. Multiple doors then opened onto a double entrance hall, or narthex. This gave access to the great open space of the nave, a rectangle measuring 229 by 245 feet (70 by 77 meters). Above this is the circular dome, 100 feet (30.5 m) in diameter, which rests on pendentives supported by four immense stone piers linked by four massive arches. These supports are not clearly evident, as in classical buildings, but are hidden behind a screen of columns on the north and south walls. On the east and west walls two half-domes are set immediately beneath the main dome; beneath each semidome are three apses. The circular dome thus seems to float unsupported 180 feet (55 m) above the nave floor. Prokopios, a historian in Justinian's court, captured the dome's effect on the viewer: "It seems not to be founded on solid masonry, but to be suspended from heaven by that golden chain." (De aedif. I, i, 23).
It is difficult to convey in words the tremendous scale of Hagia Sophia. It is the largest Byzantine church ever built; it was the largest church in medieval Christendom; it encloses a vaulted space larger than that of any building built before it. The scale of the building reflects it importance. Hagia Sophia was in many ways as symbolic of Byzantium as was the nearby Great Palace complex of the Byzantine emperors. It was the showpiece of the empire, proudly displayed to every foreign diplomat, and was equally the object of devout pilgrims and gawking tourists. It gave employment to more than 600 members of the clergy and served as the primary church of the patriarch, whose palace abutted the south facade and connected directly to the gallery. Hagia Sophia was the site of many of the empire's most important celebrations, including the investiture of new emperors. On the major feast days of the Orthodox Church the emperor and patriarch joined together to take part in the liturgy.
The interior decoration matched the splendor of its architectural underpinnings. According to Prokopios, 40,000 pounds of silver was used to decorate the sanctuary. Acres of multicolored marbles were quarried to create the columns and revetments that sheath the walls and floors. Marble was also used for many of the liturgical furnishings, such as the ambo, the elevated platform from which scriptures were read. The upper vaulting was covered with gold tesserae (cubes), which reflected the light streaming in through the tympana and dome windows. Cut marble (opus sectile ), arranged in the form of vines intertwined with fruit and birds decorated the north and south colonnades at the levels of the aisles and galleries (upper stories). Cloths woven with gold thread covered the solid gold altar and draped the interior doorways. The low screen separating the sanctuary from the nave displayed silver relief icons of Christ, the Virgin, angels, and saints. The full extent of the figural decoration of the building prior to iconoclasm is not known. After repairs to the dome in 563, a mosaic depicting a cross was placed in its apex.
In 867, after the end of Iconoclasm, Hagia Sophia was the first church to undergo official redecoration. One of the first images to be installed was the mosaic still visible in the eastern apse depicting the enthroned Virgin and Child. It was originally flanked by mosaics of the archangels Michael and Gabriel; only the latter survives today. At the same time mosaic icons of the Church Fathers were placed at the base of the tympanum. In the tenth through twelfth centuries imperial portraits were added to the south gallery and placed above the doors of the narthex, and in the fourteenth century a mosaic of Christ as Pantokrator (Ruler of All) was placed in the dome.
The building has of course undergone repairs and alterations. In the Byzantine period frequent earthquakes necessitated repairs to the dome and the strengthening of the exterior buttresses. When Constantinople fell to the Ottoman Sultan Mehmet II in 1453 the church was converted into a mosque. Christian liturgical furnishings were removed and replaced with those necessary for Muslim worship, and four minarets were added to the exterior. The Byzantine buildings that clustered around the church were replaced with Ottoman and, later, Turkish structures. The majority of the Byzantine mosaics were not removed but were painted over in the eighteenth century. Hagia Sophia is now a museum administered by the Turkish government and preserves aspects of both its Christian and Muslim history. In 1930 restoration of the Byzantine mosaics was begun and conservation work continues today on both the Byzantine and Islamic interior decorations.
Bibliography: r. cormack and e. j. w. hawkins, "The Mosaics of St. Sophia at Istanbul: The Rooms above the Southwest Vestibule and Ramp" Dumbarton Oaks Papers 31 (1977) 175–251. r. j. mainstone, Hagia Sophia: Architecture, Structure, and Liturgy of Justinian's Great Church (London 1988). g. majeska, "The Emperor in His Church: Imperial Ritual in the Church of St. Sophia" in Byzantine Court Culture from 829–1204, ed. h. maguire (Washington, DC 1997). c. mango, The Art of the Byzantine Empire 312–1453 (Toronto 1986); Materials for the Study of the Mosaics of St. Sophia (Washington, DC 1962). r. mark and a. Çakmak, eds., Hagia Sophia from the Age of Justinian to the Present (New York 1992). t. e. mathews, The Early Churches of Constantinople: Architecture and Liturgy (University Park, PA 1971). w. mÜller-weiner, Bildlexicon zur Topographie Istanbuls (Tübingen 1977). t. whittemore, The Mosaics of Saint Sophia at Istanbul; Preliminary Report on the Year's Work, 1931–32 (Paris 1933).