Hagia Sophia in Istanbul was originally built as a cathedral by Byzantine Emperor Justinian I.
The present structure was commissioned after the Nika riots destroyed an earlier church and was dedicated in 537 under Emperor Justinian I. Its architects, Anthemius of Tralles and Isidore of Miletus, created a vast central dome carried by pendentives, an engineering achievement that influenced Byzantine architecture for centuries.
Hagia Sophia served as the cathedral of Constantinople until the city’s Ottoman conquest in 1453. Sultan Mehmed II converted it into a mosque, and Ottoman additions included minarets, buttresses, and interior furnishings. Mustafa Kemal Atatürk’s government made it a museum in 1935; it was reconverted into a mosque in 2020.
The building’s name means “Holy Wisdom,” not the name of a woman called Sophia. Its interior combines Christian mosaics with Islamic calligraphy and architectural elements, reflecting its long and changing religious history.