Hagia Sophia

The world's largest dome for 1,000 years

Hagia Sophia was built 1,500 years ago — and its huge dome was the largest in the world for 1,000 years! Thanks to 40 windows, the dome seems to float in the air. The building has been a church, then a mosque, then a museum, and now a mosque again. Inside, golden mosaics sit side by side with huge medallions bearing Arabic calligraphy.

Hagia Sophia (532–537) was built in Constantinople in 5 years on the orders of Emperor Justinian; its architects were the mathematicians Isidore and Anthemius. The dome, 31 m across and 55 m high, with 40 windows, seems to 'float'; it collapsed in the earthquake of 558 and was rebuilt. For 1,000 years it was the largest church and dome in the world (until Seville Cathedral, 1520). After the Ottoman conquest of 1453 it became a mosque and gained minarets; Mimar Sinan reinforced it. A museum from 1934 to 2020, it has been a mosque since 2020. Byzantine mosaics (9th–13th century) and Ottoman calligraphy share the space. All Ottoman mosques (the Blue Mosque) were built in its style. Istanbul's historic areas are a UNESCO site (1985).

Fun facts

• The building took 5 years — 1,500 years ago, without cranes or concrete!
• Its dome was the world's largest for 1,000 years.
• Hagia Sophia has been a church, a mosque, a museum and a mosque again — it changed 'jobs' 4 times.