On 11 September 1973, a military coup was successfully launched against Chilean President Salvador Allende. British-made Hawker Hunter jets were used to attack the Chilean presidential palace, and the British government’s swift recognition of Augusto Pinochet caused outrage across the country. A solidarity campaign was launched to oppose the junta, and industrial action was taken to limit the sale of arms to Chile. While Britain’s support of Pinochet is well known, British covert action in Chile prior to the coup is not. This study will use recently declassified documents to demonstrate how, between 1960 and 1973, a secretive propaganda unit within the Foreign Office sought to prevent, and later weaken, an Allende presidency. The unit, name...