500 000 Mark

Hattingen-Ruhr was one of hundreds of German municipalities forced into emergency currency production during the hyperinflation of 1923, when the Reichsbank's output simply could not keep pace with denominations climbing toward the astronomical. City administrations, savings banks, and industrial firms all printed their own Notgeld to meet payroll and basic commerce — legal under the circumstances, if chaotic in aggregate.

The half-million Mark face value places this note squarely in the mid-1923 wave, before the autumn months pushed denominations into the billions. Birkenstock's countersignature alongside Mriey suggests dual authorization from the Magistrat, the standard civic accountability mechanism for municipally issued emergency paper.