The priory experienced its heyday during the early 16th century under provost Jakob Roselenz (1596–1629), under whom the community was reorganised and the church, previously neglected, was enlarged.

In 1840, Archduke Johann, son of Emperor Leopold II and an avid hunter, purchased the building complex from the town for the sum of 40,000 guilders for use as a hunting lodge, known thereafter as Schloss Stainz.

Today, besides offering gardens and rooms to rent for engagements, the castle houses two collections from the Universal Museum Joanneum.

The main focus of the exhibition is on the agricultural implements and the household effects of the Styrian countryside from the Stone Age to the present.

In addition to the two permanent exhibitions of the Joanneum, areas of the castle, for example the courtyard, the cellar, the arcades and the terrace, are also rented out for private events.