1247 was called a Konrad von Tanzenberg. Documented the castle was in 1300 and 1341 in the possession of the family Mordax or Mordachs. In 1513, the castle went to Maximilian I of Habsburg. The brothers Siegmund and Wolfgang von Keutschach - as nephews of the Archbishop of Salzburg Leonhard - began in 1515 with the construction of the present castle. The castle, built in four wings around a rectangular courtyard, is one of the most important Renaissance buildings in Austria.
Under the son Leonhard of Wolfgang von Keutschach probably until 1543 the castle well was completed. In 1802, this fountain was transferred to the main square of Friesach. See Stadtbrunnen Friesach. The property remained in the possession of the Keutschacher until the second half of the 17th century.
The building fell into decay in the 19th century. In 1891 Georg von Gutmannsthal acquired the castle. In 1898, the Olivetans bought the castle and began the reconstruction and conversion to a monastery building. The two lower floors correspond to the buildings of the 16th century. In the northeast tract are preserved components of the medieval castle. Instead of the former festival hall on the southwestern flank, a monastery church was built in 1898.
From 1942 until the end of the war in 1945, Tanzenberg Castle served as a repository for the holdings of the Central Library of the High School of the NSDAP. In 1946, a boarding school for candidates for a seminary was started with a grammar school. In 1953 the castle became the property of the Diocese of Gurk-Klagenfurt. 1995/1996 the facades were restored.