Recently declared as mosque Hagia Sophia was built by

Hagia Sophia was built by the Romans under Emperor Justinian in 537 AD as a cathedral later converted to a mosque by Ottomans in 1453. Greeks influenced Byzantine architecture but Romans constructed it. The structure is a masterpiece of Byzantine engineering with its massive dome and mosaics. It served as a museum from 1935 until 2020 when it was reconverted to a mosque. This site is significant for architectural history and interfaith studies symbolizing cultural shifts in Istanbul over centuries. Update (as of 2025-09-04)