Once the Church, Then the Mosque.
Masterpiece of Architectural History:
first hill

Today's Hagia Sophia (Turkish: Hagia Sophia, Latin: Hagia Sophia, English: Santa Sofia, Russian: Собор Святой Софии), literally: Sacred Wisdom or Sacred Wisdom, is the third structure built on the same site with a different architectural management than the previous ones. Hagia Sophia was accepted as the form of Byzantine architecture that preserved its body and it was said that it changed it in the history of architecture. It was built by the order of Emperor Justinian, by Anthemios (mathematician) from Tralles (today's Aydın) and Isidoros (geometrician and engineer) from Miletos (today's Balat). Its construction began in 532 and was completed in five years and opened to worship in 537 with a great ceremony. A swarm of earthquakes that struck Constantinople from May 7558 to 546 and 557 was devastating. The dome of Hagia Sophia swelled and thousands of houses could not withstand major earthquakes.

4. It is seen as a shocking betrayal among Christians. Crusader nobleman Baldwin of Flanders was crowned emperor in Hagia Sophia, but most Byzantines refused to accept him and the offensive was divided into four small independent states.

IT CONTINUED TO EXIST AS A MOSQUE IN THE OTTOMAN PERIOD

With the conquest of Constantinople by Mehmet the Conqueror, Istanbul: Konstantiniyye, Stanpolis, Dersaadet, Asitane) joined his royal mosque. III of Hagia Sophia. The historical architect Sinan, who had buttresses built on its sides so that it would not be demolished during the reign of Murad II, was inspired by the old structure and combined his style with Islamic art and finish to form the Great Mosques series. Hagia Sophia, whose domes and walls were destroyed many times during the Eastern Roman period, was not destroyed again after the repairs of Mimar Sinan, despite many major earthquakes in Istanbul.

Historical Areas of Istanbul