Danzig was composed of the Baltic Sea port of Danzig and nearby areas. The Free City was established in 1920 under the protection of the League of Nations. Hitler, resenting the loss of this German city, aimed to overturn the treaty's provisions and annexed Danzig after invading Poland in September 1939. He demanded the annexation of Danzig and extraterritorial rail access to East Prussia, leading Britain and France to guarantee Polish territory against German aggression. Germany invaded Poland on September 1, 1939, and Britain and France declared war on September 3, marking the beginning of World War II. The Stutthof camp was constructed near Danzig, initially as a civilian internment camp. In 1941, it became a security police holding center, and in 1942, it became a concentration camp. After World War II, Danzig became part of Poland, and the city was renamed Gdansk.
The free city had its own currency, the Danzig gulden, until it was annexed by Nazi Germany in September 1939. The gulden was established in 1923 to replace the German mark and had a favorable exchange rate with the pound sterling. When Nazi Germany took over Danzig, reichsmark coins and notes were declared legal tender alongside the gulden. However, to prevent abuse, the import of gulden coins and notes into the territory was prohibited shortly after. On 7 September 1939, the Reichsmark became the sole currency in Danzig.
The Bank of Danzig issued four series of banknotes between 1923 and 1938, denominated in gulden and pfennige. Notes of 5 and 10 gulden were withdrawn on the same day as the coins but could be exchanged for reichsmarks until mid-October 1939.