The United States of Greater Austria (German: Vereinigte Staaten von Groß-Österreich), is a country of roughly 101.5 million people in Central Europe. It is bordered by Germany and Poland to the north, Russia and Romania to the east, Serbia, the Papal States and Montenegro to the south and Piedmont-Sardinia, the Duchy of Parma, the Republic of Modena, Switzerland and Liechtenstein to the west. The territory of Austria covers 717,022 sq km.
The origins of Austria date back to the time of the Roman Empire when a Celtic kingdom was conquered by the Romans in approximately 15 BC and later became Noricum, a Roman province, in the mid 1st century AD—an area which mostly encloses today's Austria. In 788 AD, the Frankish king Charlemagne conquered the area and introduced Christianity. Under the native Habsburg dynasty, Austria became one of the great powers of Europe. In 1867, the Austrian Empire was reformed into Austria-Hungary, and in 1917, reformed into United States of Greater Austria.
Today, Greater Austria is a constitutional monarchy comprising sixteen federal states. The capital and largest city is Vienna. Austria is one of the richest countries in the world, with a nominal per capita GDP of $48,952 (2010 est.). The country has developed a high standard of living and in 2010 was ranked 15th in the world for its Human Development Index. Austria is a founding member of the United Nations.