Hagia Sophia was formerly a church, later a mosque, and now a museum. From the date of its dedication in 360 AD until 1453 AD, it served as a church. The building was a mosque from 1453 AD until 1931 AD, when it was secularized.

For almost 500 years the principal mosque of Istanbul, Hagia Sophia served as a model for many other Ottoman mosques.

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