The construction plans were prepared by Hovsep Aznavur, an Armenian of Istanbul origin. An international competition was conducted to produce the prefabricated parts of the church. An Austrian firm, R. Ph. Wagner, won the competition. The prefabricated parts were produced in Vienna and transported to Istanbul by ship through the Danube and the Black Sea. After one and a half years work, it was completed in 1898. The main skeleton of the church was made of steel and covered by metal boards. All the pieces were attached together with nuts, bolts, rivets or welding. The architectural styles come from the Neo-Gothic and Neo-Baroque periods.