
In the 13th century, Vienna came under threat from the Mongolian Empire, which stretched over much of present-day Russia and China. However, due to the death of its leader, Ogedei Khan, the Mongolian armies receded from the European frontier and did not return.
During the Middle Ages, Vienna was home to the Babenberg Dynasty, and in 1440 , it became the resident city of the Habsburg Dynasties, then it eventually grew to become the capital of the Holy Roman Empire and a cultural centre for arts and science, music and fine cuisine. In the 16th and 17th centuries, the Ottoman armies were stopped twice outside Vienna (see Siege of Vienna, 1529 and Battle of Vienna, 1683).
In 1804, Vienna became the capital of the Austrian Empire and continued to play a major role in European and world politics, including hosting the 1814 Congress of Vienna. After the Austro-Hungarian Compromise of 1867, Vienna remained the capital of what was then the Austro-Hungarian Empire. During the latter half of the 19th century, the city developed what had previously been the bastions and glacis into the Ringstraße, a major prestige project. Former suburbs were incorporated, and the city of Vienna grew dramatically.
In 1918, after World War I, Vienna became capital of the First Austrian Republic. During the 1920s and 1930s, it was a bastion of socialism in Austria, and was known as the "Red Vienna." The city was a stage to the Austrian Civil War of 1934, when Chancellor Engelbert Dollfuss sent the Austrian Army to shell civilian housing occupied by the socialist militia. In 1938, after a triumphant entry into Austria, Adolf Hitler famously spoke to the Austrian people from the balcony of the Neue Burg, a part of the Hofburg at the Heldenplatz. Between 1938 (see Anschluss) and the end of the Second World War, Vienna lost its status as a capital to Berlin.
In 1945, the Soviets successfully launched the Vienna Offensive against the Germans who were holding Vienna. The city was besieged for about two weeks before it fell to the Soviets. After 1945, Vienna again became the capital of Austria, was initially divided into zones by the four powers (or the four prevailing nations), and was governed by the Allied Commission for Austria. The four-power occupation of Vienna differed in some respects from the four-power occupation of Berlin: the central area of Vienna had an international zone in which the four powers alternated on a monthly basis. When the Berlin blockade occurred in 1948, Vienna was even more vulnerable because there was no airport in the western sectors. However, despite fears, the Soviets did not blockade Vienna. Some have argued that this was because the Potsdam Agreement gave written rights of land access to the western sectors, whereas no such written guarantees had been given regarding Berlin. The true reason will, however, always remain a matter of speculation. During the 10 years of foreign occupation, Vienna became a hot-bed for international espionage between the Western and Eastern blocs. The atmosphere of four-power Vienna is captured in the Graham Greene novel The Third Man and by the movie which followed.
Modern history since 1955
On May 15, 1955, the country regained its political independence and sovereignty with the "Austrian State Treaty". The Austrian Parliament immediately amended the treaty to establish Austria's future neutrality and non-alignment (similar to that of Switzerland). This peace treaty was called a state treaty because Austria had temporarily ceased to exist in 1938.
After the war, as everywhere in Western Europe, there was an enormous economic boom, among other things because of the economic aid resulting from the Marshall Plan.
In the 1970s, Austrian Chancellor Bruno Kreisky inaugurated the Vienna International Centre, a new area of the city created to host international institutions. Vienna has regained a part of its former international relevance by hosting international organizations, such as the United Nations (UNIDO, UNOV, CTBTO and UNODC), the International Atomic Energy Agency, the Organization of Petroleum Exporting Countries, and the Organization for Security and Cooperation in Europe.
Public transport in Vienna was improved by the introduction of the new U-Bahn network, the first part of which was opened in 1978. During the 1970s, Vienna became the third official seat of the United Nations, and the UNO-City was built. At the end of the 20th century, a skyline consisting of several skyscrapers was created with, among others, the Andromeda Tower and Millennium Tower on the left and right side of the Danube. Furthermore, a complex of skyscrapers was planned at the site of the Wien Mitte railway station, which might have endangered the position of Vienna's centre as a UNESCO World Heritage Site. The project has since been redesigned.
Vienna was capital of surrounding Bundesland of Lower Austria (German: Niederösterreich) until 1986, when it was replaced by Sankt Pölten. As Vienna was not geographical part of Lower Austria it was a capital outside of territory it served.
In the municipal elections of 2001, the Social Democrats regained an absolute majority. With the Liberal Forum, not gaining enough votes, only four parties have been represented in the municipal council since then. In the 2005 elections, the Social Democrats further increased their majority.