Operation Mincemeat — Spain
The body of 'Major Martin' washes ashore at Huelva — local Spanish intelligence photographs the documents and passes them to the German Abwehr, who swallow the deception entirely.
Huelva was chosen because local Spanish authorities were known to be pro-German. Adolf Clauss, the local Abwehr agent, photographed the briefcase documents and passed them to Berlin. German High Command moved a Panzer division to Greece and mined the Greek coast. The Sicily invasion on 10 July 1943 achieved complete strategic surprise — largely thanks to the documents in Major Martin's briefcase.