Holy Trinity Greek Orthodox Church in located in the historic Greek neighborhood of Vienna's Innere Stadt. Greek Orthodox churches have existed near this site since 1787, as a result of the 1781 Patent of Toleration issued by Joseph II, Holy Roman Emperor. The architect of the 1787 building was Peter Mollner.
The current building is a Byzantine Revival re-design of the Mollner building by Danish-Austrian neo-classic architect Theophil Hansen. Greek-Austrian diplomat and philanthropist Simon Sinas funded the project, one of many collaborations with Hansen in Vienna and Athens. The cathedral was inaugurated on December 21, 1858.
The exterior features two-tone brickwork and gilded archways. The elaborately ornamented sanctuary shows a stylish allusion to Baroque church architecture typical of southern Germany and Austria. A number of frescoes for the facade and vestibule were commissioned from the Austrian painter and art professor Carl Rahl, with other frescoes by Ludwig Thiersch.
Since 1963 the cathedral has been the seat of the Greek Orthodox Metropolis of Austria.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.