Hagia Sophia is a building that changed religion three times: Christian cathedral, mosque, museum, mosque again. For a thousand years, it was the largest church in the Christian world. Today, beneath Justinian's dome, Byzantine mosaics and Islamic calligraphy coexist—living testimony to a turbulent history.

Justinian's Cathedral

The first church on this site was built in 360 CE. It burned, was rebuilt, burned again. In 532, after the Nika riots, Emperor Justinian decided to build something unprecedented.

Two architects—Anthemius of Tralles and Isidore of Miletus—received carte blanche. In f...