Winston Churchill used a V sign... to symbolize "V for Victory" during World War II. ... He developed the idea from a BBC campaign.
During World War II, Victor de Lavelaye suggested that Belgians, who were chalking up the letters RAF, should add a V for victoire or vrijheid (respectively French for "victory" and Dutch for "freedom"). Since V stands for "victory" in French, Charles de Gaulle used it in every speech (from 1942–1969).[22] This idea was developed by the BBC and on 20 July 1941 a campaign was launched with a message from Churchill for occupied Europe.[23] The Channel islanders also joined in the Churchill's V sign campaign by daubing the letter 'V' (for Victory) over German signs. The United States issued the "Win the war" postal stamp with an eagle in "V" shape in 1942.
Douglas Ritchie, of the BBC European Service, suggested an audible V using the Morse code rhythm—three dots and a dash. This is also the rhythm of the opening bars of Beethoven's Fifth Symphony, and it was used as the call-sign by the BBC in its foreign language programmes to occupied Europe for the rest of the war. The irony that they were composed by a German was not lost on many of the audience or for the more musically educated that it was "Fate knocking on the door" of the Third Reich.