Rosenburg Castle was built in the 12th century by the Counts of Riedenburg. It has been rebuilt and extended many times, right up to the present day.
In the Peasants' War , the castle was conquered in April 1525 by rebels and largely destroyed. A reconstruction took place between 1556 and 1560. In the Thirty Years' War the castle 1632-1634 was sacked several times. During the War of Spanish Succession Rosenburg was conquered by the Austrians.
The well maintained property now serves as a castle museum.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.