A pole weapon is a close combat weapon with the main fighting part of the weapon placed on the end of a long shaft, typically of wood. The use of pole weapons is very old, and the first spears date to the stone age. The purpose of using pole weapons is to either increase angular momentum, and thus striking power, when the weapon is swung, or extending reach. Pole weapons are relatively cheap and simple to make, and they were fairly easy for most people to use effectively as they were often derived from hunting or agricultural tools.
Spears were probably first used as hunting weapons, either for thrusting or for throwing; the ability to strike the prey from a relatively safe distance no doubt appealing to the hunters. It was likely recognized almost immediately that they were also most useful against predators and other humans.
Massed men carrying pole weapons with pointed tips (spears, pikes, etc.) were recognized fairly early in the history of organized warfare as effective military units. On defense the men holding the spears were hard to reach; on the attack, as in the Macedonian phalanx, they were devastating to those units which could not get out of the way.
With the advent of armored fighters, especially cavalry, pole weapons frequently combined the spearpoint (for thrusting) with an axe- or hammer-head (for a swinging strike which could pierce or break armor).