Byzantine Art

Hagia Sophia, Its History, Dome and Mosaics

Built for Justinian between 532 and 537, Hagia Sophia was the largest interior in the world; its first dome fell in 558.

The interior of Hagia Sophia with the main dome and the nave
Istanbul, Hagia Sophia, interior with the main dome, 532-537, dome rebuilt 558-562. Brick, marble and mosaic. Istanbul, Turkey. A ring of windows at the base makes the dome seem to float.Photo: Jorge Láscar from Australia, CC BY 2.0, via Wikimedia Commons
The short answer

Hagia Sophia, "Holy Wisdom", was built in Constantinople for the emperor Justinian between 532 and 537 by Anthemius of Tralles and Isidore of Miletus. Its first dome fell in 558 and was rebuilt higher by 562. It was a cathedral for over 900 years, a mosque from 1453, a museum from 1935 and again a mosque since 2020.

Built in five years

In January 532 the Nika riot in Constantinople burned the city’s great church, already rebuilt once. Justinian decided to replace it with something without precedent. He chose two men known for their mathematics and mechanics more than for building, Anthemius of Tralles and Isidore of Miletus. With thousands of workers and materials gathered from across the empire, the new church was consecrated on 27 December 537, less than six years later.

Hagia Sophia with its dome, buttresses and four minarets against a blue sky
Istanbul, Hagia Sophia, exterior with the dome, buttresses and minarets, 532-537 and later. Brick, stone and lead. Istanbul, Turkey. Byzantine core, Ottoman additions.Photo: Arild Vågen, CC BY-SA 3.0, via Wikimedia Commons

The monograms of Justinian and Theodora are carved on many capitals. The writer Procopius, who saw the building new, said the dome seemed not to rest on stone but to hang from heaven on a golden chain.

A dome over a vast hall

The plan joins two ideas: a long church for processions and a centrally planned space under a dome. The main dome, about 31 metres across and some 55 metres above the floor, rests on four great arches carried by massive piers. To east and west, two half-domes extend the space, and smaller half-domes open from them. The result is an enormous single interior, for nearly a thousand years among the largest in the world, and the widest dome of its time after the Roman Pantheon.

A black and white ground plan of Hagia Sophia with a title above it
Plan of Hagia Sophia with the nave, half-domes, aisles and narthex, 532-537. Drawing. A long church with a domed centre.Photo: Greek Strategos, CC BY-SA 4.0, via Wikimedia Commons
A section drawing of Hagia Sophia with the dome, half-domes and arcades
Longitudinal section of Hagia Sophia with the main dome, half-domes and piers, 6th century. Drawing. Half-domes carry the thrust of the main dome down to the ground.Photo: Unknown author (public domain), Public domain, via Wikimedia Commons

At the base of the dome, forty windows let in light all round. Seen from below, the ring of light hides the supports, which is why the dome appears to float.

The ring of windows at the base of the dome of Hagia Sophia seen from below
Istanbul, Hagia Sophia, the ring of forty windows at the base of the dome, rebuilt 558-562. Brick and glass. Istanbul. Light separates the dome from its supports.Photo: Jorge Láscar from Australia, CC BY 2.0, via Wikimedia Commons

The first dome was shallower and pushed hard on its supports. After earthquakes, part of it collapsed on 7 May 558. Isidore the Younger, nephew of the first architect, rebuilt it higher and steeper, and the church was dedicated again in 562. That dome, repaired after later partial collapses and supported by heavy buttresses, still stands.

The mosaics

Justinian’s church was decorated with gold mosaics and crosses, with few figures. Most of the figurative mosaics we see today were made after the end of Iconoclasm, the period when religious images were banned. In the apse, a Virgin and Child enthroned was unveiled in 867. In the galleries, mosaics show emperors and empresses offering gifts to Christ and the Virgin, among them the empress Zoe with her husband. The finest is the Deesis, made around 1261, where the Virgin and John the Baptist turn to Christ in prayer.

The mosaic of the Virgin and Child enthroned in the apse
Istanbul, Hagia Sophia, apse mosaic of the Virgin and Child enthroned, unveiled 867. Glass mosaic. Istanbul. The first figurative mosaic after Iconoclasm.Photo: Photograph: Myrabella, Public domain, via Wikimedia Commons
The Deesis mosaic with Christ between the Virgin and John the Baptist, partly lost
Istanbul, Hagia Sophia, the Deesis, c. 1261. Glass mosaic. Istanbul, south gallery. Christ between the Virgin and John the Baptist.Photo: Photograph: Myrabella, Public domain, via Wikimedia Commons
A mosaic of the empress Zoe and her husband beside Christ with Greek inscriptions
Istanbul, Hagia Sophia, mosaic of the empress Zoe and her husband offering gifts to Christ, 11th century. Glass mosaic. Istanbul, south gallery. Imperial patrons in the church’s upper level.Photo: Photographer: Myrabella, Public domain, via Wikimedia Commons

Visitors left their own traces. On a marble parapet in the gallery, someone carved runes, usually read as a name, Halfdan, probably a Scandinavian guard or traveller of the ninth or tenth century.

Runic letters scratched on a marble surface below a sign
Istanbul, Hagia Sophia, runic graffito scratched on a gallery parapet, 9th-10th century. Marble. Istanbul. A Norse visitor’s name, Halvdan, scratched into stone.Photo: Not home at English Wikipedia, Public domain, via Wikimedia Commons

Cathedral, mosque, museum, mosque

For more than 900 years Hagia Sophia was the cathedral of Constantinople, the setting of imperial coronations and great feasts, the model for Byzantine art and architecture. After the Ottoman conquest on 29 May 1453, Sultan Mehmed II converted it into a mosque. Minarets were added, the mosaics were gradually plastered over or left in shadow, and a mihrab facing Mecca, a minbar and later large calligraphic roundels were installed. The architect Sinan strengthened the structure with buttresses in the sixteenth century, and the dome of Hagia Sophia became the model for the great Ottoman mosques of Istanbul.

The gilded mihrab and minbar of Hagia Sophia in a half-dome niche
Istanbul, Hagia Sophia, mihrab, minbar and calligraphic roundels, 15th-19th century additions. Marble, wood and painted panels. Istanbul. The Ottoman furnishings of the mosque.Photo: Dosseman, CC BY-SA 4.0, via Wikimedia Commons

In 1934 the government of the Turkish Republic made it a museum, opened in 1935, and many mosaics were uncovered. In July 2020 a ruling of Turkey’s Council of State annulled the 1934 decision, and Hagia Sophia became a mosque again; the first Friday prayers were held on 24 July 2020. It remains open to visitors outside prayer times, and the figurative mosaics on the ground floor are covered or kept in shadow during prayers.

Where to see it

Hagia Sophia stands in Sultanahmet, in the historic centre of Istanbul, opposite the Blue Mosque and a short walk from the Basilica Cistern. It is part of the UNESCO World Heritage Site of the Historic Areas of Istanbul.

Sources

  • UNESCO World Heritage Centre, “Historic Areas of Istanbul”.
  • Procopius, Buildings 1.1.
  • R. J. Mainstone, Hagia Sophia: Architecture, Structure and Liturgy of Justinian’s Great Church (London, 1988).
  • Metropolitan Museum of Art, Heilbrunn Timeline, “Hagia Sophia, 532-37”.
  • Reuters and BBC (July 2020) on the Council of State ruling and the first prayers.

Quick facts

Place
Istanbul, Sultanahmet, Turkey
Monument
Hagia Sophia (Ayasofya), cathedral, mosque, museum and mosque
Date
532-537; dome collapsed 558, rebuilt by 562; mosque 1453; museum 1935; mosque again 2020
Architect
Anthemius of Tralles and Isidore of Miletus; second dome by Isidore the Younger
Material
Brick and mortar, marble, glass mosaic
Dimensions
Main dome about 31 m in diameter, about 55 m high; forty windows at its base
Status today
Mosque open to visitors outside prayer times; part of the Historic Areas of Istanbul (UNESCO 1985)