Greek Orthodox Patriarchate

Istanbul has been the center of Eastern Christian Church since Constantine moved the Roman capital there in the 4th Century. Since today, the city remains the home of the Ecumenical Patriarch of Constantinople, who is recognized as the "first among equals" of all Orthodox spiritual leaders. Istanbul is also important as being the center of one of the biggest debates of the Christian world since the 6th century as The Greek Orthodox Patriarchate is located in Fener neighbourhood of Fatih district.
After the conquest of Constantinople by the Turks, Sultan Mehmed The Conqueror granted legal protection to the Greek Orthodox Partriachate in Istanbul. The Patriache, was considered as a vezier in the Ottoman Empire and also attended Divan meetings in the palace. He was exempted from taxes, had legal decision rights for the issues of the orthodox people of the empire, and he perhaps had more power over the Orthodox citizens in the empire than ever before during the Ottoman Empire.
it has a great importance because of artifacts and relics, which include the patriarchal throne, believed to date back to the 5th century; three rare mosaic icons; the Column of Flagellation to which Jesus was tied and whipped; and the tombs of female saints.