The longbow has been the common type across North Western Europe since the neolithic.
What distinguishes the English use of the longbow is the way in which it was employed to counter numerically superior forces.
Forget all this nonsense about Welsh bows being the precursor of the English warbow, that's just mindless recycling of uninformed opinion from an earler "authority".
War bow draw weights have developed in all warbow cultures to keep pace with defensive developments. The result is that cavalry bows came to be typically in the 90lb to 120lb range and infantry bows to a median of around 120lb to 150lb.
Before dedicated war bow development, a heavy hunting bow would have sufficed in war, but the race to achieve greater range and penetration with heavier arrows leads to escalation in draw weight.
Part of the fame of the English bow derives from the fact that the myth of the longbow has since Tudor times been accepted as an integral part in the development of the myth of Englishness.
Given that this process carried through the growth and fall of Empire, starting life as a political tool when a predominantly Norman ruling minority had the good fortune to have left in place a considerable amount of Anglo Saxon social infrastructure, which gave later Kings an armed social class in serjeanty that functioned coherently on the battlefield.
More coherently, for some time, than those who had the misfortune to attack them, since the key development was the use of massed archery in a defensive position against greater numbers that were often mismanaged with a less coherent chain of command.
Other warbow cultures (China, Korea, Japan, Mamluks, Scythians, Mongols etc) have their own variations on this theme.
Rod.