Hochosterwitz is 664 metres (2,178 ft) above sea level[1] on the rim of the historic Zollfeld plain north of Magdalensberg, about 7 km (4.3 mi) east of Sankt Veit.

A settlement site since the Bronze Age, the rock was first mentioned in an 860 deed issued by Louis the German, King of East Francia, donating several of his properties in the former principality of Carantania to the Archdiocese of Salzburg.

In 1209 one Herman of Osterwitz, who held the hereditary office of the cup-bearer at the ducal court in Sankt Veit,[2] accompanied Duke Bernhard of Carinthia to the coronation of Emperor Otto IV in Rome.

In his book Change the Austro-American psychologist Paul Watzlawick (1921–2007) renders a popular tale of the siege of the castle by the troops of Countess Margaret of Tyrol (Margarethe Maultasch).

According to legend first noted by the medieval chronicler Jakob Unrest and later by Jacob Grimm, Margaret, cheated by the Austrian House of Habsburg of her inheritance claims to Carinthia upon her father's death in 1335, invaded the duchy; her forces were however deceived and withdrew when the garrison of Hochosterwitz slaughtered its last ox, filled it with grain and threw it over the wall, pretending it still had so many provisions in stock that they could be used as projectiles.

On 5 October 1509, Emperor Maximilian I handed the castle as a pledge to Matthäus Lang von Wellenburg, then Bishop of Gurk.

A 1:25 miniature scale model of Hochosterwitz Castle may be seen at Minimundus, a popular tourist attraction in Klagenfurt approximately 20 kilometres (12 mi) away.