How did the 2 fingered salute meaning "phuck off" originate?

Battle of Agincourt. The froggies had the most cavalry and thought they were going to wipe the floor with the brits and allies. They were so confident they threatened to cut the bow fingers off the english bowmen, who were feared for their ability, when they won.
The bowmen slaughtered the french cavalry with their volleys and they waved their two fingers at the french as they trooped past in defeat.
I think it originated from when the cavaliers and the round-heads were at war - when one caught the other, they would cut off their fingers, so the '2 fingered salute' came about as a way of celebrating that they still had their fingers. Something like that!
I think is something to do with archers in days off old and how they used to be punished by having there 2 fingers cut off for being poor shots or something.

Up yours they said, I've still got my fingers
The origin of this gesture is highly speculative, but is quite possibly up to 2500 years old. It is identified as the digitus impudicus ('impudent finger') in Ancient Roman writings [1] and reference is made to using the finger in the Ancient Greek comedy The Clouds by Aristophanes. It was defined there as a gesture intended to insult another.

It has long been told that the famous "two-fingers salute" and/or "V sign" derives from the gestures of English archers, fighting at Agincourt. The myth claims that the French cut off two fingers on the right hand of captured archers and that the gesture was a sign of defiance by those who were not mutilated.
As the above but I thought it was the English archers taunting the French who would cut off the fingers you need to draw a bow
Before the days of guns, long-bowmen were the major fire power in an army. Upon capturing enemy long-bowmen, the archer would have his bow fingers cut off, thus rendering him incapable of firing his weapon. The 2 finger salute was given by English bowmen to the French as I sign that they still had their bow fingers and were thus still a potent force. The gesture only later became a term of abuse.
Middle ages. When English were fighting French, the English bowmen were a deadly weapon. When they were captured, they had first two fingers of right hand chopped off so they could not fire a bow. So the English bowmen used to wave their first two fingers at the French to say 'Come and get us if youre hard enough' (or some such). Hence two fingers is an insult!
The two finger salute comes from the old times when wars were still fought with bow and arrow. The "French" (Normans) would cut off the middle and index finger of the "English" longbow men, if the got their hands on them. The salute meant originally, look I still got my fingers so get lost or.. So I suppose that even then it actually meant f**k off or else.
after the french defeat at Agincourt by the English archers, if an archer was caught by the french he would have his forefinger and middle finger cut off, as these were the fingers used to draw the bow it made him useless as an archer.
The V salute was the English way of telling the french we still have our fingers and you are fckd
I believe Oz has hit the nail on the head.
Archers. During the 100 Years Wars the French, who were decimated by the longbowmen of England at several battles, got into the habit of chopping off the index and middle fingers of captured English archers. This stopped them from being able to draw the string of the longbow and fire arrows. It became the habit of the English to give the two fingered salute to the French to show they still had the two fingers to draw the bow. Cocking a snoop with catapult fingers!
English archers , the long bowmen of middle ages. If the French captured them, they would cut off the two fingers used to draw a bowstring, thus incapacitating him as a future threat. Two raised fingers (vee-sign) was adopted as a vulgar sign that the archer was still a potent threat.
It actually originated in a war when British archers were captured by the French they had their "arching" fingers cut off. When they weren't captured the archers put their fingers up to annoy the French as they were saying "YOU HAVEN'T GOT ME"!