On a marble plaque, the builder of this bastion, Count Johann Ernst von Purgstall, tells us the following about the construction process:

“During the reign of Emperor Leopold I, the builder of the empire, what you see here was built at my expense. Do not be surprised that it exceeds the normal scale in many respects, for I was compelled to follow the contours of the rock during construction. Johann Ernst, Count of Purgstall, Privy Councillor to His Imperial Majesty, and his beloved wife Katharina, Countess of Purgstall, born Baroness Galler – 1685.”

Emperor Leopold promised the then lord of the castle a construction subsidy of 4,000 gulden. This, however, was never paid. Despite this empty promise, Count Purgstall gave this mighty structure the emperor’s name.