The whole purpose was to create this idea that there was this Prussian juggernaut.
Prussian militarism was unlovely, to be sure, but the Kaiser was no Führer.
Supposedly, he and his troops drank it after defeating the Prussian army in 1809.
All in all, it seems that Prussian blue was synthesised for the first time around 1706 by the Swiss immigrant Johann Jacob Diesbach in Berlin. [Jens Bartoll and Bärbel Jackisch, "Prussian Blue: A Chronology of the Early Years," "Zeitschrift für Kunsttechnologie und Konservierung" 24, No. 1, 2010]Early German sources refer to it as Preußisches Ultra-Marin and berliner blau. Prussic acid (1790), is from French acide prussique, so called in reference to prussian blue pigment, to which it is chemically related.