The problem facing Allied planners in early 1943 was obvious: after securing North Africa, the next logical target was Sicily—geographically inevitable, strategically essential, and therefore exactly where the Germans expected the next blow. MI5 officer Charles Cholmondeley and Royal Navy intelligence officer Ewen Montagu proposed to solve this problem with a dead man.
The Plan
Operation Mincemeat required a corpse, a cover identity convincing enough to survive professional scrutiny, and documents detailed enough to be credible to German intelligence analysts. The body was found—a Welsh tramp who had died of rat poison—and given the identity of 'Major William Martin' of the Royal Marines. Martin was equipped with personal papers establishing his life: a photograph of his fiancée, love letters, receipts from his London club, a letter about an overdraft. And in his briefcase, chained to his wrist: letters between senior British officers discussing Allied plans—specifically, indicating the coming offensive would target Greece and Sardinia, not Sicily.
The German Response
Major Martin's body was released from a British submarine off the Spanish coast near Huelva on April 30, 1943. Spanish authorities—officially neutral but German-leaning in their intelligence sharing—retrieved him, passed the documents to the Abwehr (German military intelligence), photographed them, and returned them with seals that appeared unbroken but had been opened and resealed. German intelligence analysts accepted the documents as genuine. Hitler personally ordered reinforcements to Greece. Rommel was sent to Greece to assess the defenses.
Sicily
When Allied forces landed in Sicily on July 10, 1943, the island's defenses were weaker than they would have been without Mincemeat. The German and Italian divisions that might have reinforced Sicily were in the wrong place. The operation's success was real and measurable in the German order of battle on July 10.