There were a total of four castles with the name Weißenegg in the Austrian provinces, of which the castle near Ruden was probably the ancestral castle of the Weißeneggers. The oldest known descendant of the Weißenegger family is said to have been Wülfing von Wizzeneck, who is said to have lived around 1120. The castle was first mentioned in a document in 1243 as dominus de Wizenekke. Dietmar von Weißenegg, a ministerial of the diocese of Bamberg, appears several times in documents between 1244 and 1263. In the 13th and 14th centuries, the Weißeneggers were an important noble family in Carinthia, they provided several bishops and were also active in the military. From the year 1300 Weißenegg was the seat of a district court, which also included Ruden. In 1332 the property was sold to the Lords of Walsee. Eberhard von Walsee († 1363), who had no descendants, inherited the castle and dominion from his cousins Ulrich and Hermann I von Cilli. The Counts of Cilli stayed on Weißenegg until 1425, then Hermann II von Cilli exchanged Weißenegg and Hartneidstein with the bishopric of Bamberg for the lordship of Mauthenberg (Hohenmauthen/Muta). Weißenegg remained in Bamberg until 1759, when the diocese sold its estates in Carinthia to the Austrian Empire. The castle was already deserted at this point. In 1775 Maximilian Thaddäus Freiherr von Egger acquired the castle, which from then on remained in the possession of his descendants for over a century. In 1885 the barons Ferdinand and Karl Helldorf bought the property, and in 1936 the extensive forests with the ruins passed to the Leitgeb family of industrialists from Kühnsdorf, who are still the owners today.