Altenburg was built by Konrad von Hohenstaff after he and his brother, Leutold, had lost their old ancestral seat, the Staffburg Castle near Sankt Veit an der Gölsen.
By the end of the 14th century at the latest, Altenburg was no longer owned by the Hohenstaff-Altenburg-Hohenberg ministerialis family as Hans der Alachter sold the Meierhof below Altenburg to Ulrich von Pergau in 1386.
At this time, Lilienfeld Abbey had preserved Altenburg as a ruin, but the monks of the monastery allowed it to continue to decay until the walls completely disappeared.
It was later taken over by the Singer family, who sold it to the Austrian Children's Friends (German: Österreichische Kinderfreunde) in 1930.
[2] In 1947, the castle stables came into the possession of the Lower Austria regional group of the SPÖ Free School Children's Friends.