Hagia Sophia

The building that stands today was put up in barely five years. In January 532 the Nika riots burned down the previous church on the site, and within weeks Emperor Justinian I had started a far more ambitious replacement, designed by two scholars rather than master masons: Anthemius of Tralles, a mathematician, and Isidore of Miletus, a geometer. It was dedicated in 537. Its central dome, carried on four curved triangular pendentives over a square plan, created the largest enclosed interior of its age and changed what architects believed was possible. For nearly a thousand years it was the cathedral of Constantinople and the seat of the Ecumenical Patriarch, and it remained the largest church in the world until the twelfth century.

The dome proved as fragile as it was bold. The original collapsed after an earthquake in 558, and Isidore the Younger rebuilt it about six metres higher and ribbed, so that its thrust would fall more steeply into the walls; later partial collapses were repaired in turn. The forty windows around its base make the dome seem to hover on a ring of light while also lightening its load. The interior is a layering of eras: marble revetment and columns of the sixth century, Byzantine gold mosaics of emperors, empresses, Christ and the Virgin, and the Ottoman fittings added after 1453, when Mehmed II converted the church into a mosque. In the southern part of the building a ninth-century runic scratch, read as Halvdan was here, is thought to be the work of a Viking mercenary.

Hagia Sophia was secularised as a museum in 1935 and reclassified as a mosque in 2020, a decision that drew strong criticism abroad. It is a working mosque again: most of the ground floor is reserved for worship, while visitors see the interior from the upper galleries. Women need to cover their hair, and access is limited around prayer times. A major structural programme to strengthen the dome against earthquakes began in 2025, so expect scaffolding. Around it the old city keeps the Sultan Ahmed Mosque, built in 1616 to outshine it, the Basilica Cistern beneath the site of Justinian's civic basilica, and the older church of Hagia Irene.

Getting there

Hagia Sophia is in the Sultanahmet quarter of the historic peninsula, about 1.3 km from Eminönü. Istanbul Sabiha Gökçen (SAW) on the Asian side is 30.3 km away; Istanbul Airport (IST), the city's main hub, is about 36 km. The T1 tram line, which runs through the old city from Kabataş via Eminönü to Bağcılar, is the simplest way to reach the area.