The Wikipedia article of the day for August 26, 2017 is Operation Bernhard.
Operation Bernhard was an exercise by the Nazis to forge British bank notes. The initial plan was to drop the notes over Britain to bring about a collapse of the economy, but the operation was closed in early 1942 after its head, Alfred Naujocks, fell out of favour with his superior officer, Reinhard Heydrich. It was reopened in July as a counterfeiting operation to finance German intelligence operations. Prisoners were sent to Sachsenhausen concentration camp to work under SS Major Bernhard Krüger, producing British notes until mid-1945 worth between £130 and £300 million. Counterfeit notes from the operation were used to pay the Turkish agent Elyesa Bazna—code-named Cicero—for his work in obtaining secrets from the British ambassador in Ankara, Turkey. Another £100,000 helped to free the Italian leader Benito Mussolini in the Gran Sasso raid in September 1943. The operation was dramatised in a 1981 BBC comedy-drama miniseries, Private Schulz, and in a 2007 Austrian film, The Counterfeiters.