The Two-Finger Salute of Derision
Long considered an exceedingly vulgar sign in Britain (though virtually unknown in North America) this gesture had no obscene significance when it first appeared hundreds of years ago on the battlefields of France. At that time the French army, in fear of the English archers, gave notice that all longbow men they captured would have the first two fingers of their bowstring-pulling hand cut off thus ensuring they would never be able to shoot another arrow.
The English archers, to show their fingers were still intact, before and after the battle, would make this gesture of defiance to the French soldiers.
It is not to be confused with the simple W.W.II victory sign made famous by Winston Churchill. That gesture (later inanely purloined by such idiots as Michael Jackson) was, is, made with the palm of the hand facing the recipient. A very significant difference.