The purpose of black propaganda has been described as the 'disruption of the enemy's will and power to fight on'.
In the early days of the Second World War, black propaganda from Britain never indicated its origins, but often gave the impression that it came from resistance groups.
The first propaganda leaflet drops were carried out on the night of 3 September 1939, when the conflict was only hours old. Leaflet drops over occupied Europe were also used for Royal Air Force reconnaissance to identify future bombing targets.
As the war progressed, leaflets often stated clearly where they were produced: 'This leaflet was dropped by American airplanes', or 'Brought to you by your friends in the RAF'. Eventually they were 'delivered' using artillery shells, rather than being shoved through a hatch in the floor of an aircraft.
In 1941, the Political Warfare Executive (PWE) was set up by the British Government mainly to develop black propaganda. The PWE worked through the BBC to broadcast propaganda to Europe. It was also responsible for Allied information and mis-information plans at the time of the D-Day landings in June 1944.
Millions of publications were created – leaflets, newspapers, stickers, stamps and posters – and airdropped over Nazi-occupied Europe. Leaflets were produced in many languages, including French, German, Danish, Norwegian, and Czech.
Scottish journalist Peter Ritchie Calder became the PWE's Director of Plans and Operations in 1942. The images on this page are examples from his extensive collection of black propaganda held by the National Library of Scotland.