The House of Dietrichstein was one of the oldest and most prominent Austrian noble families originating from the Duchy of Carinthia. The family belonged to the high nobility (German: Hochadel). The Nikolsburg branch was elevated to the rank of Prince of the Holy Roman Empire in 1624, while a member of the Hollenburg branch was elevated to the same dignity in 1684. The family held two territories with imperial immediacy – the Principality of Dietrichstein, along with castles in Carinthia and Moravia, and the Barony of Tarasp in Switzerland.