My camera battery died the morning we visited. I have no photographs from inside the Hagia Sophia. What I have instead is the memory of standing inside it — which is enough, for now.
The Hagia Sophia had been one of the most significant buildings of my architectural education — a structure I had studied in plan, section, and elevation, understood structurally, written about, and dreamed of standing inside. When I finally did, in March 2007, the building was a museum. It had been a museum since 1935. By the time you read this, it is a mosque again — a change I’ll return to.
The Building and Its History
The Hagia Sophia — Aya Sofya in Turkish, meaning “Holy Wisdom” in Greek — was originally conceived by Constantine the Great upon his conversion to Christianity and built in its current form under the Eastern Roman Emperor Justinian I in the 6th century as a Byzantine basilica. It was, at its completion in 537 CE, the largest interior space in the world — a record it held for nearly a thousand years.
The structural achievement at its center is the dome: 184 feet above the floor, spanning approximately 102 feet in diameter, supported by four concave pendentives that transition the circular base of the dome to the square of the central structure below. Two hemicycles extend the central nave to 200 feet in length; three minor apses close the east end; arcades surround aisles and galleries to the north and south. The narthex — the entrance vestibule — extends the west end. The whole composition creates a vast, unified interior volume that the structure seems almost impossibly light for its age and mass.
You can smell its 1,400 years of age. That is not a poetic formulation but a literal observation — the building carries a particular quality of ancient stone, accumulated air, and layered history that is physically present.
In 1453, Sultan Mehmed II of the Ottoman Empire took Constantinople, renaming it Istanbul and converting the basilica into the first imperial mosque of the city, Aya Sofya Mosque. The Christian elements were removed or covered — the mosaics plastered over, in deference to Islam’s prohibition of representational imagery. Ottoman additions followed across the subsequent centuries: four minarets, fountains, mausoleums, the great Islamic calligraphy medallions hanging in the central nave bearing the names of Allah, Muhammad, and the first caliphs. One minaret was built in red brick; the other three in white limestone and sandstone — different eras of Ottoman construction visible in the materials.
The building remained a mosque for nearly five hundred years. In 1935, Atatürk — as part of his sweeping program of secular modernization — converted it to a museum, a gesture that acknowledged both its Christian and its Islamic heritage without formally belonging to either. Several of the Byzantine mosaics were painstakingly restored: the gold ground reappearing where it had been plastered over, the Byzantine basket capitals atop the columns visible again, the faces of saints and emperors emerging from centuries of concealment. Both cultures and their historical value were, in the restoration process, respected.
The Experience of the Space
Walking into the Hagia Sophia for the first time is not like any other architectural experience I can compare it to. The dome overhead seems too large for the structure supporting it, the interior too bright and too vast for a building of this age. The central nave is not dark in the way of later Gothic cathedrals — the clerestory windows ringing the base of the dome flood the space with light, the gold mosaics catching and distributing it throughout the interior.
The calligraphy medallions hang enormous in the nave — four meters in diameter each, the Arabic script of the names they carry legible from across the space. The Byzantine basket capitals on the columns below are among the most refined examples of their type surviving anywhere. The Iznik tiles added during the Ottoman period line the lower walls in geometric patterns of blue and white, a different tradition of ornament from the mosaics above, both present simultaneously.
The building holds all of its history in the same space without resolving the tension between them. That is not a failure but the point. No building has served as Greek Orthodox cathedral, Roman Catholic cathedral, and imperial mosque — three distinct religious traditions at the centers of three distinct civilizations — and survived to tell all three stories simultaneously. The Hagia Sophia does.
2020: A Mosque Again
In July 2020, President Erdoğan signed a decree reconverting the Hagia Sophia from museum to active mosque — reversing Atatürk’s 1935 secularization and returning it to religious use for the first time in 85 years. The decision was met with widespread international concern, particularly regarding the fate of the Byzantine mosaics, which are covered with curtains or lighting adjustments during prayer times.
The building remains open to non-Muslim visitors outside of prayer hours, with no admission fee. Shoulders and heads must be covered. The mosaics are accessible — though the visitor experience has changed with the reintroduction of active worship.
I was there in its museum years. The building was one thing then and is another thing now — which is, of course, what it has always been. The Hagia Sophia has been converted, reconverted, destroyed, rebuilt, desecrated, and restored across fifteen centuries. Its capacity to absorb transformation without ceasing to be itself is the most remarkable thing about it.
The structural argument it makes — a dome of that scale, held in the air by pendentives and half-domes, flooding the nave with light through windows at its base — remains exactly what it was in 537 CE. Whatever the building is designated, the stone makes the same claim.
I will go back.
Hagia Sophia connects to the Turkey Atlas, the Byzantine Style Guide, and the Islamic Style Guide. Read about Istanbul — the city surrounding it →