It is 8 April 1793, and the long "March of the First Democrats" begins.

April 8, 1793, "the march of the first democrats".
After the French Revolutionary troops had occupied large parts of the Rhineland in 1792, a democratic republic (Mainz Republic) was organised under French rule in the imperial city of Mainz.
After the Imperial Army and Prussian troops regained the French-occupied Rhineland, the search for democratically-minded members of the population began. Many were arrested and the so-called "March of the First Democrats" began. The prisoners' route went from Mainz and Frankfurt towards the Taunus past the Bockenheimer Warte (shown here). Accompanied by soldiers, the prisoners were taken to the Königstein fortress i.T. and imprisoned there.

https://www.artstation.com/artwork/R3eYbA
http://www.koenigstein-burg.de/rundgaenge/
http://www.koenigstein-burg.de