100 000 000 000 Mark

Cologne was among the municipalities forced to print its own emergency currency during the hyperinflation spiral of late 1923, when Reichsbank notes could not be produced fast enough to keep pace with collapsing purchasing power. This hundred-billion-mark note was issued under the authority of Konrad Adenauer, then Oberbürgermeister of Cologne — nearly three decades before his chancellorship. The signature here belongs to the same man who would later anchor West Germany's postwar monetary stability, which gives the note a particular biographical irony.

Printed locally by Fritz Elsner, the note was obsolete within weeks of issue as the Rentenmark reform of November 1923 extinguished the old currency entirely.