50 Kroner Heilmann type I

Gerhard Heilmann was primarily known as an ornithologist — his 1926 book on the origin of birds earned him international scientific recognition — and his work for Nationalbanken represents an unusual intersection of natural history illustration and banknote design. The series bearing his name ran across a notably long issue window, with specimens from the early 1910s and the late 1920s sharing the same basic plate design despite the considerable monetary turbulence Denmark experienced after the First World War.

Denmark returned to the gold standard in 1927 at the pre-war parity, a deflationary decision that kept these notes in active use through a period of real economic strain. Notes from the final years of the type carried purchasing power that had been fought over politically for nearly a decade.