The history of Austria covers the history of Austria and its predecessor states. In the late Iron Age Austria was occupied by people of the Hallstatt Celtic culture (c. 800 BC), they first organized as a Celtic kingdom referred to by the Romans as Noricum, dating from c. 800 to 400 BC. At the end of the 1st century BC, the lands south of the Danube became part of the Roman Empire. In the Migration Period, the 6th century, the Bavarii, a Germanic people, occupied these lands until it fell to the Frankish Empire established by the Germanic Franks in the 9th century. In the year 976 AD, the first state of Austria formed. The name Ostarrîchi (Austria) has been in use since 996 AD when it was a margravate of the Duchy of Bavaria and from 1156 an independent duchy (later archduchy) of the Holy Roman Empire (962–1806).
Austria was dominated by the House of Habsburg and House of Habsburg-Lorraine from 1273 to 1918. In 1806, when Emperor Francis II of Austria dissolved the Holy Roman Empire, Austria became the Austrian Empire, and was also part of the German Confederation until the Austro-Prussian War of 1866. In 1867, Austria formed a dual monarchy with Hungary: the Austro-Hungarian Empire. When this empire collapsed after the end of World War I in 1918, Austria was reduced to the main, mostly German-speaking areas of the empire (its current frontiers), and adopted the name, the Republic of German-Austria. However, union with Germany and the chosen country name were forbidden by the Allies at the Treaty of Versailles. This led to the creation of the First Austrian Republic (1919–1933).