Hagia Sophia: the architects, light, and rebuilding of a great dome
Hagia Sophia in Constantinople was rebuilt for Emperor Justinian by Anthemios of Tralles and Isidoros of Miletus between 532 and 537. Its name means Holy Wisdom. The new church opened on December 27, 537, with a vast central space beneath a dome supported by an elaborate arrangement of arches and smaller vaults. The structure combined immense scale with colored stone, gold decoration, and carefully admitted light. It also required major repairs: the original dome collapsed in 558, and a higher replacement was completed in 562.
The site had already held two churches. Emperor Constantius dedicated the first in 360. Originally known as the Great Church, it acquired the name Hagia Sophia around 430. The first building was lost in riots in 404, and its successor was dedicated under Theodosius II in 415. That second church burned during the Nika revolt of 532. Justinian ordered rebuilding immediately afterward. The cathedral was the bishop's seat in the imperial capital, and the new commission replaced a major religious institution lost during urban upheaval.
Justinian assembled labor from many places for the project. Anthemios organized the workers and prepared models for the proposed construction, with Isidoros sharing responsibility for the design. The architects brought mathematical expertise to the commission. The central dome spanned more than 31 meters. Four great arches carried its weight within a system that also included half-domes, smaller half-domes, and arcades. Between the arches, curved triangular surfaces narrowed downward toward the supports and broadened upward toward the circular base beneath the dome.
Windows near that circular base admitted daylight above the central space. Light helped obscure the visual weight of the structure, giving the dome an appearance of suspension rather than heavy masonry resting on supports. Procopius compared its effect to a golden chain descending from heaven. The impression was integral to the building's reception: the light-filled interior could seem radiant from within. The sanctuary, reserved for priests, displayed expensive gifts of metalwork, while the surrounding architecture drew the eye upward through arches toward the crown.
Stone supplied a different kind of brilliance. Colored marble panels and ornamental inlays covered interior surfaces. Reused ancient columns supported the arcades. Marble from the quarries of Proconnesus appeared in patterned wall decoration. Craftsmen cut and joined slabs so that their veins formed designs across squares and eight-sided figures. Paul the Silentiary celebrated the variety of these surfaces, comparing their effects to painted patterns. His description placed the carefully matched stone alongside the enormous dome as a major feature of the church's visual richness.
Artificial illumination continued that effect after dark. Lamps hung on chains through the central space and aisles, with others positioned to the east and west and along the upper walls. The lighting spread across different levels of the building. Paul imagined its radiance reaching sailors approaching Constantinople, giving the church a place within the city's maritime setting as well as its religious life. His praise connected the experience of its shining interior with the broad visibility and symbolic importance of the imperial church.
The ambitious structure proved vulnerable. After the first dome's collapse, rebuilding raised its profile, changing the form above Justinian's original interior. Later earthquakes and ground movement caused further damage, although the principal fabric remained that of the sixth-century commission. Decoration changed too. A cross originally occupied a medallion at the summit amid relatively restrained gold ornament. After the Byzantine period of Iconoclasm ended in 843, figural mosaics were added. The interior therefore accumulated decoration across centuries rather than receiving every surviving mosaic during the first building campaign.
The Ottoman conquest in 1453 brought another transformation. Mehmed II converted Hagia Sophia into a mosque. Minarets were erected around the complex, exterior buttresses strengthened the structure, and whitewash covered Christian mosaic images. The building remained a major religious monument while acquiring elements associated with a different tradition of worship. In 1934, the Turkish government designated it a museum, and restoration made mosaics visible again. The Christian and Ottoman alterations both formed part of the structure inherited by modern conservators.
In July 2020, a further change of status prompted an official UNESCO response. The Turkish decision had been announced without prior discussion or notification. Hagia Sophia belonged to the World Heritage property known as the Historic Areas of Istanbul. UNESCO called for protection of its universal heritage value and prior discussion of changes affecting its fabric, contents, management, or public access. The building's long history had joined a sixth-century engineering achievement to later religious and political transformations. Conservation now concerned the surviving architecture and decoration created throughout that history.
- Metropolitan Museum of Art, Emma Wegner, Hagia Sophia, 532–37 — www.metmuseum.org
- Fordham University, Procopius, Description of Hagia Sophia — sourcebooks.web.fordham.edu
- Fordham University, Paul the Silentiary, The Magnificence of Hagia Sophia — sourcebooks.web.fordham.edu
- UNESCO, Statement on Hagia Sophia, July 10, 2020 — whc.unesco.org