Located in Sultan Ahmed Square, opposite the Blue Mosque. It was the main church of the Byzantine Empire until the Ottoman Empire occupied Istanbul in 1453. It was founded in 325 AD and has collapsed twice since the earthquake. It was rebuilt three times in 532 and officially completed in 537. The building was the largest church in the world at the time. After 1453, the Ottoman Empire transformed it into a mosque and built two new spires.
After the official establishment of the Republic of Turkey, it was changed into a museum for people to visit. It is a famous historic building in Turkey that has undergone two major baptisms and is also a model of Byzantine architecture. There are also mosaic murals representing Christianity, and you can understand the history of the time while enjoying the beauty of the art of the Byzantine Empire. In the past 500 years, as one of the most important mosques in Istanbul, it has also become the blueprint of many mosques in the Ottoman Empire.