When this building was constructed in 537 and until it was converted into a mosque in 1453 it was either a traditional church. In 1453 this building was converted into a mosque where the people of Muslim Community could offer their religious duties. This place remained a worshipping place for the Muslim society for almost 400 years from 1453 to 1931. At this point of timer the edifice was closed as a mosque and was converted into a museum. The authorities of this place opened this museum for the public on 1st February, 1935.
The construction of this massive mosque (originally a cathedral) was well known because of its huge cupola and the architects are of the opinion that this dome has changed the style and basis of Byzantine planning for construction of building structures. This building remained the biggest church for over one thousand years when other churches were built which were much huge than this building.
In the year 1453, Constantinople was conquered by the Turks under the leadership of Mehmet II and ordered that this Church be transformed into a mosque. All the floorings of the building were completely removed and new floorings were put in their place which depicted the Muslim culture. It was decided to construct the minarets which were four in number, plus the Minber for the IMAM (This is a raised platform from where the Imam addresses the congregation) to deliver the Sermon of Friday prayers and other important Muslim festivals. The designer was also ordered to complete the Mihrabs (a semicircular door in the wall which gives the direction that the Muslims should face the Qibla in Mecca) in the mosque, which is considered to be an important part of any mosque. The Qibla is the direction which indicates the track of the Ka’Aba.
This mosque was the center of all Muslim gatherings, until the time when other mosques were constructed in Istanbul. This mosque served as a beacon light for the construction of other mosques during the Ottoman Rule
The church was in a very poor state of affairs when Mehmet II occupied the place. He immediately ordered the makeover of the church and its transformation into a mosque. He himself attended the First Friday prayers immediately after its completion as a mosque.
The many buildings near the mosque became the part of the foundation which was formed to run the affairs of the mosque. These constructions were made a part of the foundation formed to run the day to day affairs by the issuance of an order by the ruler.
The mosque had two minarets on the Northeast and Southwest corner. The earthquake that hit Istanbul in 1509 destroyed one of the minarets. In the middle of the 16th century, the ruler ordered the construction of the two minarets which were diagonally opposite to each the on the east and west corners of the structure
Once again the structure of the mosque indicated signs of destruction of the mosque, when, the then ruler, ordered the reinforcement of the mosque with the addition of strong supporting pillars in the outer skirts of the building. The engineer’s name was MIMAR SINAN.
The reinforcement of the building was ordered, by Sultan Abdulmecid, under the two brothers of Swiss origin during the period 1847-1849. The Swiss brothers reinforced the cupola and the arches and the pillars. They also redecorated the interior and exterior places of the mosque. It is estimated that around 800 workers took part in this reinforcement which took place during the two years from 1847 to 1849. When the work of redesigning was completed, the mosque was opened for the public.