In 1780, Prince Dmitri Mikhailovich Galitzin, the Russian ambassador in Vienna, acquired forested property from Field Marshal Count Franz Moritz von Lacy, situated uphill of what was then the village of Ottakring.
When Julius' son, Prince Moritz de Montléart, acquired the property after considerable legal battles, he gave it to his wife Wilhelmine (née von Arnold) and named the castle "Wilhelminenberg".