Adaptive Reuse and the Hagia Sophia

At the site where the Hagia Sophia currently stands were once several iterations of smaller churches, mainly basilican in form. It wasn’t until 537 CE, in order to appease the public after his brutal suppression of the Nika riots, that Emperor Justinian I ordered the church to be built in its most familiar form.

The structure stands at 182 feet tall, with its most prominent feature being a large central dome. The dome is supported by pendentives, which were revolutionary for the time; these are spherical, triangular structures that curve inward from a square base. This allows for a large, open space below–a key feature, as the dome was meant to evoke heaven itself. Forty arched windows line the base of this large dome, but more than 200 windows light the structure overall, some of them fitted with stained glass. Smaller half-domes and a variety of columns also line the building’s facade, the latter of which were primarily recycled from older Roman structures. At its base, the structure takes a rectangular shape. Brick, mortar, wood, and metal comprise the outer and supportive structures, while marble, pumice stone, and glass were used for interior decorative features. Carved relief panels and mosaics depicting religious scenes can be found all along the interior.

After the Ottoman conquest of Constantinople in 1453, Sultan Mehmed II ordered the church to be converted into a mosque rather than having it destroyed. Much of the structure was preserved, but a number of Islamic elements were added as well: minarets, which are high platforms in which the call to prayer is announced; a mihrab, which is a prayer niche that often indicates the direction of Mecca for worshippers; and large calligraphic roundels. Many of the Byzantine mosaics were covered in plaster.

One reason the Ottomans may have chosen to embrace the Hagia Sophia rather than destroy it, beyond practicality, was that it linked the Ottomans to the Romans and symbolically legitimized their inheritance of the city. Other Byzantine structures were also used in other Ottoman architectural projects. 

In 1934, the mosque was converted into a museum and secular space through a decree under Mustafa Kemal Ataturk, the founding father of the Republic of Turkey. It was converted back into a mosque by order of President Erdogan in 2020.