Basic spear was a very useful weapon during all the middle ages, because its production was cheap and handling was simple. Anyone could arm themselves with them from infantry soldiers to peasants. In the majority of cases, spears were of little use, but with experience and training, the large line of spearmen could be very effective.
Pole weapons evolved during the medieval period, gradually reaching a point in which formations of infantry trained for their management were extremely effective. More advanced variants had a spearhead with one or more weapons below. This additional weapon could be a large knife, axe, hammer or a pike.
Spears evolved as a response to the cavalry and brought with them the revival of an ancient Greek phalanx-like formation. The horses did not dare to charge against a disciplined troops armed with long extended spears. A dense formation of long raised spears also provided some protection against the arrows.
Infantrymen first learned to sit behind wooden stakes nailed into the ground to overthrow the cavalry. They later learned to deploy spears, pikes and other long range weapons. This gave the power of movement to the formation and allowed the anti-cavalry strikes. In a skirmish, weapons added to the end of the spears were used as to bring down the riders of their mounts by pulling them or pushing them, and to cause injury to the rider or the horse. Although the men who wore armor were not defenseless once taken down, but they were temporarily at a disadvantage until they managed to get up.