Hagia Sophia or “Church of Divine Wisdom” was built by the Byzantine Emperor Justinian in the sixth century as a monument to Christianity and the rise of the eastern Roman Empire. Hagia Sophia remained for centuries the biggest church in the world only being surpassed by the church of St Peter in Rome several centuries later. Hagia Sophia is a spectacular feat of architecture especially considering the limited building methods that were available at the time of construction. Only the best materials were used for building Hagia Sofia, including marble walls and flooring and gold wall and ceiling decorations. The distinguishing feature of Hagia Sofia is the vast dome surrounded by several semi domes, designed to give the visitor an impression of the greatness of God. Unfortunately, Hagia Sofia was damaged soon after it was built due to the earthquake line that Istanbul lies on. Over the centuries it has been repaired several times. Even today there are ongoing repairs or restoration taking place.
Hagia Sophia was turned into a mosque under Sultan Mehmet after he took control of Istanbul from the Byzantines in 1453 CE and remained so for hundreds of years. It was then that the so-called 'Turkish period' started, and several major alterations were made. Under the rule of the Ottomans, Hagia Sophia attained Islamic features, such as the mihrab, the minbar, and the four minarets outside.
The art works surrounding the mihrab include the best samples of Turkish pottery and calligraphy. The large calligraphy inscribed medallions, rounded plates of 7.50 m diameter, hung from the walls were inscribed on by Kazasker Mustafa Izzet Efendi, a famous Ottoman calligrapher. The names of Allah, Muhammed, Omer, Osman, Ali, Hasan, Ebu Bekir and Huseyin are inscribed there. On the sidewalls of the mihrab there are plates written by various Ottoman sultans.
The tombs of Sultan Selim II, Sultan Mehmet III, Sultan Murat III as well as some of their relatives, fountain of Sultan Mahmut I, primary school, soup kitchen, library, Sultan Abdulmecit's meeting place and the mosque timekeeper's (astronomer's) house may be found in the vicinity of the Aya Sophia Museum. All of these, especially the tombs with their interior design, pottery and architecture, are excellent examples of the Ottoman tradition.