By the time allied armies took Paris in March 1814 Gustav Schlabrendorf's authorship from Paris of a series of German-language polemical yet scholarly anti-Napoleon books and tracts was no secret. In Prussia and the westerly German speaking lands that had been part of the French empire till 1813 he was something of a celebrity. The advancing Prussian forces greeted him with enthusiasm and the invitation to return "home" to Prussia was renewed. (However, somehow he was unable to obtain the necessary travel documents.) After the coalition armies entered Paris, it is reported that the assistance he rendered the military was so important that The king awarded him the (recently inaugurated) Iron Cross.