If not for British ingenuity, who knows how World War II would've ended?

On April 30, 1943, while World War II was still raging, German soldiers discovered a washed up body in the coast of Spain. Based on documents found on the body, they identified the person as British Major William Martin. The Germans however found more than just clues to his identity, they also found official documents pointing to an Allied invasion of Sardinia. The Germans believed the documents and mustered forces in Sardinia. The Allies however were really aiming for Sicily. With German attention in Sardinia, Sicily fell easily into Allied hands and effectively set in motion the events that would lead to the downfall of Italian dictator Benito Mussolini. Major Martin was in effect only an elaborate ruse.

Fact or Fiction?
Fact!