Hagia Sophia: Istanbul
537 · place
On 27 December 537 the emperor Justinian entered a new church in Constantinople whose central dome appeared to rest on nothing at all. Hagia Sophia, the church of Holy Wisdom, had been built in five years by two men who were mathematicians rather than builders by training, Anthemius of Tralles and Isidore of Miletus. Its dome is about thirty one metres across and rises some fifty five metres above the floor, and a ring of forty windows around its base makes the whole weight seem to float on light.
The building was the largest enclosed space in the world for close to a thousand years, and its influence on architecture, from later Byzantine churches to Ottoman mosques, is difficult to overstate. The first dome was too shallow and fell after an earthquake in 558. It was rebuilt higher and steeper and has stood, with repairs, ever since, in a city that sits on an active fault.
Its history follows the history of the city. It was the principal church of the Orthodox world for nine hundred years, was looted during the Fourth Crusade, and became a mosque after the Ottoman conquest of 1453, when minarets were added and the great calligraphic roundels were hung. In 1935 the new Turkish republic turned it into a museum, and mosaics that had been plastered over were uncovered. In 2020 it became a working mosque once more.
Visitors still look up in the same way. Beneath the plaster and the paint the building carries Christian mosaics and Islamic calligraphy in the same room, and it remains one of the few places where fifteen centuries of a city's arguments about itself are visible in a single glance.