The Central European land that is now Austria was settled in pre-Roman times by various Celtic tribes. The Celtic kingdom of Noricum was later claimed by the Roman Empire and made a province. Present-day Petronell-Carnuntum in eastern Austria was an important army camp turned capital city in what became known as the Upper Pannonia province. Carnuntum was home for 50,000 people for nearly 400 years.[23]

Middle Ages
After the fall of the Roman Empire, the area was invaded by Bavarians, Slavs, and Avars.[24] Charlemagne, King of the Franks, conquered the area in AD 788, encouraged colonisation, and introduced Christianity.[24] As part of Eastern Francia, the core areas that now encompass Austria were bequeathed to the house of Babenberg. The area was known as the marchia Orientalis and was given to Leopold of Babenberg in 976.[25]