Close order formation

A close order formation is a military tactical formation in which soldiers are close together and regularly arranged for the tactical concentration of force. It was used by heavy infantry in ancient warfare, as the basis for shield wall and phalanx tactics, to multiply their effective weight of arms by their weight of numbers. In the Late Middle Ages, Swiss pikemen and German Landsknechts used close order formations that were similar to ancient phalanxes. Around the American Civil War (1861–1865), such organizations of soldiers became uncommon since improvements in firearms and artillery had made any such dense formation increasingly hazardous and less effective. The technological concentration of increased firepower to fewer soldiers had rendered the close order formation obsolete by the end of the 19th century. Modern infantry now use skirmish order, which is effectively the opposite of close order. Images from the Sumerian kingdom from the 3rd millennium BC clearly show men with spears in close order formation. That tradition continued in the ancient world with the phalanx formation of the Greeks and later the Ancient Macedonians. The Greek phalanx fought with the aspis, a large round bronze faced shield and a large spear. The frontage per man was the width of the shield (about 3 ft), and the normal formation depth was four to eight men. The later Macedonian phalanx used a smaller shield but replaced the spear with a sarissa, a long pike used in two hands. The normal frontage per man remained the same, but the normal depth grew to 16 ranks. An innovation was the introduction of a "locked shield order" (synaspismos), with a frontage of only about 18 in. The Roman legions also fought in close order by using the pilum and the gladius on a similar frontage per man to the phalanx. In the early Middle Ages, infantry used the shieldwall, a formation in which shields were held edge-to-edge or overlapped. Close order was routinely used by infantry in the later Middle Ages, the intention being to avoid the enemy penetrating and disrupting their formation.