History of ownership
Allentsteig Castle was founded by the Kuenringers around 1000.
Until around 1390 it was owned by the Lords of Kamegg-Kaya.
In the 14th century it was owned by the Sonnbergers, in 1332 by Eberhard V of Walsee (* around 1290; † 1371), Captain of the Enns.
1367 Kuenringers; 1380 Lords of Maissau. Otto IV, the last of the Maissau family, leased Allentsteig to his follower Hans Hager in 1409.
Granted to the Lords of Puchheim in 1440.
In 1486 the mercenary leader Spanowsky occupied Allentsteig in addition to Zwettl from 1458 to 1490 on behalf of King Matthias Corvinus, actually Hunyadi King of Hungary.
Around 1500, the Hager family was granted the lordship. Between 1544 and 1570, they had the medieval castle converted into a Renaissance palace.
From 1599, Paris von Sonderndorf, a staunch defender of his faith and opponent of the emperor. This led to the town being plundered several times during the Thirty Years' War and finally occupied by imperial troops. In 1629, Hans Friedrich von Sonderndorf lost his property through confiscation.
The new owners were the Barons von Rappach until 1694; through marriage, the property came to Count Ernst August von Falkenhayn. In 1682 and 1752, there was severe damage from fires.
1804 Baron Leopold von Hahn, 1816 the Pereira-Arnstein family and after 1884 the Princes of and of Liechtenstein.
In 1918, Baroness Maria von Preuschen inherited the estate. When the German Reich built the huge Allentsteig military training area in 1938, which at times housed up to 60,000 soldiers, it made the castle the headquarters of the command. It retained this function when it was handed over to the Republic of Austria after the Russian occupation from 1945 to 1955.