Vienna and infact much of Austria is country with abundance of history. Hofburg imperial palace is just one example of it's magnificent history.
This particular building was built in 13th century and was used as the palace for the rulers of the country for hundreds of years. Today, it is where the president resides and works. Similar to the function of the White House, or 10 Downing Street London. It wasn't until 1918 that the complex was used for this purpose. Prior to that, it was the political centre of the monarchy.
This is the very place that Emperor Franz Joseph would hold his audiences. Actually this is the place where you'll find the Imperial apartments occupied by the Emperor and his wife, Elisabeth. You can go inside and take a tour of the 24 rooms which have been restored to the highest standards of historical accuracy.
The places you want to visit are the Montoyer Wing, which is where the Hall of Festivities are held. St. Michaels Wing, which is where you'll find the Church on the opposite side.
The redoute wing was once an opera house which was later converted by the Empress Maria into dance and concert halls, together they form the Redoute Wing. This is the place where the baroque entertainment would take place, events such as royal balls etc. It is said that the famous composers, Joseph Haydn and Pagnini and even Liszt have performed there.