In 1606 the prince-archbishop Wolf Dietrich von Raitenau built a palace for his mistress, Salome Alt and their children outside the Bergstraßtor gate of Salzburg.
The exact reason for building the palace was an attack of gout that the archbishop had suffered during the winter of 1604/1605, and a stroke that paralysed his right arm fr four months.
The extent of how much Wolf Dietrich enjoyed living in his new home is evident from a plaque inscribed in Latin, and brought by Markus Sittikus to the Salzburg Residenz: Chosen by God's mercy, I rule over the rushing, streaming Salzach.
The name Altenau was derived from Salome Alt's family name, and the term Au, referring to a low island in the river Salzach which at the time had a very broad bed, stretching from the Mönchsberg wall of the city as far as the area of the present Schwarzstraße (embankments were not added to the river until after 1852).
A chronicler describes the building as a large and magnificent palace or castle, surrounded by beautiful gardens of all kinds of shrubs, trees and fruit.