. Built in Neo-Byzantine style, it serves as the cathedral church of the Patriarch of Bulgaria and it is one of the 50 largest Christian church buildings by volume in the world.

It is one of the oldest functioning churches in Europe build in early 4-th century. The building, a cylindrical domed structure built on a square base, is famous for the 12th-, 13th-, and 14th-century frescoes inside the central dome

The church was first mentioned in the 16th century and was constructed at the place of a former Roman religious building. It is today a monument of culture known for its mural paintings from the 14th, 15th, 17th and 19th century depicting biblical scenes.

The cathedral, rebuilt at its previous location after it was destroyed by Allied bombing raids during World War II, was inaugurated on 21 May 2006 in the presence of Cardinal Secretary of State Angelo Sodano, Dean of the College of Cardinals. The foundation stone of the new cathedral was laid personally by Pope John Paul II during his visit to Bulgaria in 2002.

The construction is a nave one with three domes in Romanian style of 18th century. The exceptionally beautiful frescoes inside were done by the famous icon-painter masters, the altar and furniture are of high quality oak wood with fine carving.

This is one of the first churches in Sofia which was built after the liberation of Bulgaria when Sofia became a capital of Bulgaria.