Skirmishers.

The battlefield innovation that followed militia spearmen was the provision of skirmishers, sometimes referred to as light troops. Skirmishers were usually equipped with missile weapons such as bows, slings, or javelins. Their job was to harass the enemy infantry columns with missiles, causing casualties, shaking morale, and breaking discipline prior to the clash of the spearmen columns. If the enemy's column could be disorganized before the clash, it was likely that their morale would break upon contact with a disciplined column of erect shields and thrusting spears.

Skirmishers required more training than militia spearmen, however. Where the spearmen found relative safety within their columns, skirmishers acted independently, running forward to loose their missiles and then running back if necessary. There may have been others nearby conducting the same type of attack, but there was not the comfort of a solid wall of friendly troops nearby. Light troops were not expected to meet the enemy face-to-face. Fighting independently they did not have the strength of numbers and could not stand against a solid infantry column. They looked for weakness and opportunity, rushed in, and fell back before strength.

Skirmishers did not usually carry shields. Their defensive strength was the ability to move more quickly than the spearmen columns moving in step and carrying cumbersome shields and spears. They hit and ran, taunting the enemy and trying to make them as uncomfortable as possible.Slingers were the easiest skirmishers to equip. All they required was a cloth sling a pocket of stones. Additional ammunition could be found lying on the battlefield. Javelins were no more difficult to provide than spears, but once thrown they were usually lost. Artwork from the second and third millennium rarely shows javelin throwers holding more than two weapons. Javelin throwers must have waited until the infantry columns were closing to be effective. Skirmishers used the simple bow of limited range. The much more powerful composite bow was known in the second millennium, but was too costly to manufacture in quantity for light troops.

The addition of light troops to armies was an important military innovation. This was the beginning of combined arms_the provision of different types of troops for different battlefield missions and their use in concert to achieve victory. Generals thereafter were required to know how best to use infantry and skirmishers together and how to defend against the combination.The most famous skirmisher in history was David, who slew the Philistine Goliath with a stone from his sling.