Around 15 BCE, most of what is now Austria was annexed into the Roman Empire, marking the start of "Austria Romana," a period that lasted about 500 years. The area became part of the province of Noricum, which had previously been a trade partner and military ally of Rome. Under Emperor Claudius (41–54 CE), Noricum’s borders followed natural landmarks like the Danube River and the Vienna Woods. Later, Emperor Diocletian (284–305 CE) divided the province into Noricum ripense (north) and Noricum Mediterraneum (south). To the west lay Raetia (covering Tyrol and Vorarlberg), and to the east lay Pannonia (including today’s Burgenland).
The Roman empire in the time of Hadrian (ruled 117–138 AD), showing, on the upper Danube river. © Andrein
The Romans established key cities in the region, many of which still exist today. Vindobona (modern Vienna) served as a military camp on the Danubian frontier. Other major settlements included Juvavum (Salzburg), Brigantium (Bregenz), Valdidena (Innsbruck), and administrative centers like Virunum and Teurnia. Roman infrastructure, including roads and trade networks, linked these towns and contributed to regional prosperity.
The Danube limes—a fortified boundary—protected the empire from Germanic tribes such as the Marcomanni and Quadi. Archaeological remains from the period, including settlements at Magdalensberg and Kleinklein, reflect the cultural integration of Roman practices.
Christianity began spreading into Austria by the 2nd century, with organized church structures emerging by the 4th century. After the fall of Roman authority, missionary efforts intensified, especially through figures like Saint Rupert and Saint Virgil, who played a key role in converting the region after the Bavarii’s arrival.