The Church of the Holy Wisdom Aya Sofya (Hagia Sophia) is one of the most impressive buildings in Istanbul. Aya Sofya was originally Byzantine church then Ottoman mosque and now itís a museum. The first Byzantine church was built there at fourth century by Constantine the Great the first Christian emperor, but unfortunately nothing remains from that time.
The second church built by the emperor Theodosius the Great burned down during the Nika riots of 532. Some small fragments from this church were excavated and can be seen as part of current museum exposition. The current form of Aya Sofya was built between 532 and 537 by Emperor Justinian I and designed by architects Isidore of Miletus and Anthemius of Tralles.
Aya Sofya was the seat of the Orthodox Patriarch of Constantinople and a principal setting for church councils and imperial ceremonies for almost 1000 years. The building was damaged by earthquakes a couple of times and must be repaired. In 1204 Aya Sofya lost its power and importance and the most of the treasure was divided among the Greek Orthodox and Roman Catholic churches. Nevertheless Aya Sofya remained a functioning church until Tuesday, May 29, 1453 when Sultan Mehmet the Conqueror entered into the city of Constantinople and decided to convert the church into the mosque.
The church decoration such as bells, altar, iconostasis, and sacrificial vessels must have been removed and mosaics covered, while Islamic features like mihrab, minbar, and the four minarets outside the mosque were added. Aya Sofya was used as principal mosque of Istanbul for nearly 500 years and become a model for other Istanbul mosques such as the Blue Mosque. In 1935, it was changed to museum by the first Turkey president Mustafa Kemal AtatŁrk. Nowadays, Aya Sofya is favorite touristic site together with Blue Mosque and Topkapi palace.