Torn between long bow and rifle. Before adaquate ranged weapons, the sword wielders ruled the lands, iron clad and invincable by ordinary peasants. The Welsh long bow changed tht, and the rifle put the final nail in the coffin of the armored knights, thus changing the landscape from fuedalism to the Rennaisance, (spelling?).
My take. The tool that truly moved a people from substinance living, to having enough food to branch out into studies of what made life better was none of the above - it was the horse collar. A horse harnessed with straps couldn't work much more than two or three humans, and ate the same. With a proper collar, a horse could do far more work, thus cultivating more, and freeing up people for other things, like developing looms, forges, etc.