St. Stephan Bulgarian Church which belongs to Bulgarian minority is may be the most interesting church of Istanbul. Bulgarian residents of Ottoman Empire previously performed their religious rituals in the churches of Fener Orthodox Patriarchy. And probably under the influence of nationalism, Bulgarian people received permission from the state to have their own churches. At first, a small wooden church was built on the area between Balat, where the church is located today and Fener, by the Golden Horn coast. Later, an activity began to build a larger church. Since the ground was weak, iron frame method was preferred for being lighter, rather than concrete.

The project of the St. Stephan Bulgarian Church was made by Hovsep Aznavur who was an Armenian born in Istanbul. There was an international competition for the production of prefabricated parts of the church and an Austrian company named R Ph Wagner won this competition. The parts manufactured in Vienna were carried to Istanbul by vessel through the Danube River and Black Sea. It was finally situated on its present place in 1898 after a work of 1.5 years.

The supporting profiles of the St. Stephan Bulgarian Church was made of steel and they were covered with sheet iron sheets. All parts were joined with each other by bolt, screw nut, rivet or welding. As for the architectural style, it has neogothic and neobaroque elements.