20 Korona

Hungary's wartime finances had been straining under the joint Austro-Hungarian apparatus for years, and by 1918 the state was issuing notes under its own name rather than through the k.k. Privilegierte Österreichische Nationalbank — a shift that reflected the accelerating political disintegration of the Dual Monarchy as much as any fiscal logic. P#21 belongs to the final phase of that imperial currency framework, printed in the last year of the war before the collapse of November 1918 rendered the entire series politically obsolete almost immediately upon issue.

Overstamping by successor states complicates the collecting picture significantly. Romanian, Czechoslovak, and Yugoslav authorities all applied control stamps to circulating Korona notes in their newly acquired territories, and unstamped examples of this type were frequently invalidated without compensation.