Following the Spanish Civil War, 1936-39, Spain became a nationalist, militarized dictatorship under the rule of General Francisco Franco. Although Francoist Spain was officially neutral during World War II, in practice the authorities leaned strongly toward the Axis powers. Spain’s economic devastation following its Civil War precluded it from joining the Axis war effort, but Spain supplied Germany with essential raw materials and served Fascist Italy and Nazi Germany by allowing intelligence networks to operate across the country, and passing on intelligence. In Operation Mincemeat, the collusion of the Spanish authorities with the German intelligence and military hierarchy—and Britain’s foreknowledge of this behavior—was crucial in setting the trap of false information.

During World War II, Naval Intelligence was the foremost of the three military services’ intelligence units, as the Admiralty acted as operational command for Bletchley Park, the center of the British decoding and deciphering operation. This included “Ultra,” the codename for the work of intercepting and deciphering German official communications generated by the German Enigma machine, the Lorenz SZ 40/42 machines, and the Hagelin machine. Britain’s ability to read these communications was crucial to the war effort, enabling the intelligence services to follow and understand the intentions and behavior of the German high command. As Operation Mincemeat shows, British intelligence knew the identities and personalities of key German officers and was able to manipulate this for advantage. They were also able to track the disinformation of Operation Mincemeat as it travelled from Spain through the German command structure, increasing control. As it was essential for Germany not to know that Britain had the consistent ability to decipher their communications, naval intelligence created a fictional spy network called “Boniface,” and engineered deliberate “mistakes” to deflect suspicion.