Krumperk Castle was probably built in the late 13th century by the noble family Rabensberg from Koprivnik. The predecessor of the current castle is first mentioned in 1338 as a possession of Herkules of Krumperk, of the noble house of Kreutberg. By the 15th century, it belonged to the house of Rusbach, which sold it to Engelhand Zellenperger in 1410 under the name Turn Chraw-perg. Valvasor notes that it had once been called either Thurn unter Kreutberg or Thurn zu Kreutberg, although there is confusion as to which of these names referred to Krumperk Castle and which to the ruin of Koprivnik (Rabensberg) Castle near Moravče.
At the end of the 16th century, the male Zellenperger line became extinct, and the castle passed by inheritance accord to the older branch of the house of Rauber, one of the most prominent noble families in 15th and 16th century Carniola, who were later elevated to barons. The best-known member of the family was Adam von Rauber, who participated in the Battle of Sisak. At its height, the Krumperk lordship contained the settlements of Dob, Ihan, Krtina, Brezovica, and Studenec.
The Raubers replaced the old castle with the current building in 1580. Their line eventually became extinct; the daughter of the last Baron Rauber was the mother of the historian Johann Weikhard von Valvasor. The next owners, in 1631, were the Rasp family, followed by the counts Thurn-Valsassina, then in 1840 the barons Rechbach, who in 1928 moved to Austria after selling the estate to its final private owner, Stanka Pogačnik, a landowner from Ruše near Maribor.
After World War II, the castle was nationalized and stripped of its furnishings. The communist authorities converted the structure into a sanatorium for wounded military officers; in 1953, it was given to the Municipality of Domžale, which subdivided it into apartment housing. In 1985, the Krumperk holdings were partitioned; the castle went to Agrokombinat and the estate was taken over by Biotechnical Faculty of the University of Ljubljana, which established an equestrian center.
Today, the castle is the subject of a denationalization proceeding and is in a fairly poor state of repair.
References:Carlsten is a stone fortress built on the orders of King Carl X of Sweden following the Treaty of Roskilde, 1658 to protect the newly acquired province of Bohuslän from hostile attacks. The site of Marstrand was chosen because of its location and its access to an ice free port. Initially a square stone tower was constructed, but by 1680 it was reconstructed and replaced by a round shaped tower. Successive additions to the fortress were carried out, by the inmates sentenced to hard labour, until 1860 when it was reported finished. The fortress was decommissioned as a permanent defense installation in 1882, but remained in military use until the early 1990s.
The fortress was attacked and sieged twice falling into enemy hands. In 1677 it was conquered by Ulrik Frederick Gyldenløve, the Danish military commander in Norway and in 1719 by the Norwegian Vice-Admiral Tordenskjold. At both occasions the fortress was returned to Swedish control through negotiations and treaties.