About 400 BC the Celts come to Carinthia. They interbred with the resident Illyrians and founded the kingdom Noricum with the capital in Magdalensberg about 200 BC. About 15 BC Noricum was annexed by the Roman Empire without any violence. In 45 AD it was transformed into a Roman province. The Romans built Virunum as the center. In the 5th century the Romans were more and more driven out by Teutonic tribes.

In the 6th century Slovenian tribes came in the country and founded the principality Carantania which capital was the Karnburg castle in the Zollfeld area. In the 8th century Carinthia got under the rule of Bavaria and 796 Carinthia got a part of the empire of Charlemagne. 896 Arnulf of Carinthia became the emperor of the Frank empire.

In 976 Carinthia was seperated from Bavaria and got an own dukedom. 1122 - 1269 the Spanheimer from the Rheinpfalz region were the feudal lords of Carinthia. In 1335 Carinthia was connected to Austria. In the 15th and 16th century the country was attacked by the Turks. They raided and destroyed many villages. The new religion which was disseminated by Luther in the 16th century was oppressed during the counter-reformation and Protestant citizens were driven away. 1797 - 1813 the country was occupied by Napoleonic troops. The revolutionary year 1848 also had negative consequences for the mining and the iron industry in Carinthia.

After the First World War the peace treaty of St. Germain (1918) established the connection of the Kanaltal valley, where Austrians and Slovenians lived, to Italy. The South-Eastern part of Carinthia where many different languages are spoken continued to remain to Austria after a plebiscite in the year 1920. In 1938 Carinthia together with Austria became part of the German Reich. After 1945 Carinthia was occupied by the British troops. The international treaty of 1955 guaranteed once again the frontiers of 1920.