Vienna is the capital of the Republic of Austria and also one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.7 million (2.3 million within the metropolitan area), it is by far the largest city in Austria, as well as its cultural, economic, and political centre. It is the 10th largest city by population in the European Union. Vienna is host to many major international organizations such as the United Nations and OPEC. Vienna lies in the east of Austria and is close to the Czech Republic, Slovakia and Hungary. In 2001, the city centre was designated a UNESCO World Heritage Site and in 2005 an Economist Intelligence Unit study of 127 world cities ranked it first equal with Vancouver for the quality of life. This assessment was mirrored by the Mercer Survey in 2009.
The English name is Vienna, while the German name is Wien, and the names of the city in most languages, are thought to be derived from the Celtic name of a settlement, but opinions vary on the precise origin. Some claim that the name comes from Vedunia, meaning "forest stream," which subsequently became Venia, Wienne and Wien. Others claim that the name comes from the name of the Roman settlement Vindobona, probably meaning "white base/bottom," which became Vindovina, Viden and Wien.
Founded around 500 BC, Vienna was originally a Celtic settlement. In 15 BC, Vienna became a Roman frontier city (Vindobona) guarding the Roman Empire against Germanic tribes to the north.
In the 13th century, Vienna came under the 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 AD, 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.
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 (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 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.
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.