On January 14, 1941, Victor de Laveleye, former Belgian Minister of Justice and director of the Belgian French-speaking broadcasts on the BBC (1940–1944), suggested in a broadcast that Belgians use a V for victoire (French: “victory”) and vrijheid (Dutch: "freedom") as a rallying emblem during World War II. By July 1941, the emblematic use of the letter V had spread through occupied Europe, and on July 19, Winston Churchill put the British government’s stamp of approval on the V for Victory campaign in a speech, from which point he started using the V hand sign.
Credit: G-Man