Close order formation A close order formation is a military tactical formation wherein soldiers are close together and regularly arranged for the tactical concentration of force . At about the time of the U . S . Civil War ( 1861 – 1865 ) , such combat formation s of soldiers became unnecessary , when improved small arms and artillery made a death trap of open ground for any formation so exposed . Hence , the technological concentration of much firepower to fewer soldiers rendered the close order formation obsolete by the end of the 19th century . History . Pre - gunpowder era . Antiquity . Images from the Sumer ian kingdom from the third millennium BC clearly show men with spear s in close order formation . The close order tradition continued in the ancient world with the phalanx formation of first the Greeks and later the Macedonians . The Greek phalanx fought with the aspis , a large round bronze faced shield and a large spear . Frontage per man was the width of the shield ( about 3 ft . ) and normal formation depth 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 . Normal frontage per man remained the same but normal depth grew to 16 ranks . An innovation was the introduction of a " locked shield order " ( synaspismos ) with a frontage of only about 18 inches . The Roman legions also fought in close order , using the pilum and gladius , on a similar frontage per man to the phalanx . The Middle Ages . In the early Middle Ages , infantry used the shieldwall , a formation where 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 . A common literary image was that an apple should not be able to pass between their lances . In the 15th . century , the Swiss developed pike tactics which used closely packed deep columns . A reconstruction of the deployment of Zürich forces in 1443 gives a formation 56 men wide by 20 deep , the formation having a width of 168 ft . and a depth of 140 ft . The Swiss main formation at the Battle of Morat consisted of 10 , 000 men and experiments have estimated its area of as little as 60m . X 60m . The knightly cavalry of the Middle Ages could also fight in close order , stirrup to stirrup . The growth in firepower . The sixteenth century . The period 1490 - 1520 saw the emergence of a consensus in military thinking that armies should be increasingly ordered on the battlefield and that neat , rectalinear formations were the key to this . The uniform bodies of pikes would be ordered based on an area occupied by a soldier of three paces frontage and seven paces depth , the soldier being positioned at the centre of this rectangle . Pikes did not stand alone on the battlefield , however , and new formations of horns or sleeves of shot were developed to support these pikeblocks with firearms . At the end of the 16th . century , a system called countermarch ing was developed , which enabled an exchange of ranks of shooters . This led to the development of thinner formations and set tacticians on the road to developing the linear fire tactics of the 18th . century . On horseback , the old knightly tactics slowly gave way to new tactics involving firearms and these led to the development of pistol - armed cavalry known as reiters . Reiters specialised in manoeuvering in deep , close formations and practiced a tactic known as the caracole where successive ranks of men rode forward , shot and retired to reload . 17th and 18th centuries . In the 17th century , European armies expanded their use of firearms , which were at first matchlock weapons like arquebus es . These were later supplanted by unrifled musket s fired by a flintlock mechanism , which became the weapon of choice because it could be fired relatively rapidly ( six shots per minute ) . Because of their poor accuracy , these weapons were typically used in line formations where a commanding officer would order volley fire to increase the chances of inflicting casualties on the enemy . These tactics were used through the 18th century . Line formations were , however , not without risks . Line commanders and other field officers were often highly visible targets , and became the target of sniper attacks as rifling technology , which significantly increased the range and accuracy of firearms ( at the expense of a substantially reduced rate of fire ) , began to see increased use in the late 18th century . Fortifications were designed to break up formations ( reducing the effectiveness of volley fire ) , or to expose them to enfilading fire . In the latter , an enemy who could fire down the length of a line with an inaccurate weapon ( or cannons loaded with anti - personnel grapeshot ) greatly increased his chances of hitting something . Another formation that saw use was the infantry square . Designed as a defense against cavalry charges , an infantry battalion would form a square with the unit ' s standard in the center , along with reserve forces . This formation enabled the defenders to fire on cavalry on all sides of the formation , although there was some risk that fire from one square might reach other squares formed nearby . The effectiveness of a square depended on the ability of the infantry to hold their ground against cavalry charges . The eclipse of close - order formations . During the 19th century , advances in firearms technology rendered the use of close formations obsolete . Widespread use of rifled guns ( including cannons ) , and the advent of reliable breech - loading weapon s and automated weapons like the Gatling gun , altered the tactical landscape . These weapons fired at greater range with accuracy , and technological improvements in aiming them also simplified the targeting of large bodies of enemy forces . A major exception was in the Anglo - Zulu war after the Battle of Isandlwana . After that humiliating defeat , the British army found that close - order infantry formations were necessary to concentrate firepower to break the Zulu warriors ' formidable massed charges . One of the last occasions involving the deployment in the face of the enemy of substantial numbers of British troops in close order , occurred at the Battle of Magersfontein during the South African War . The Scottish Brigade , comprising 3 , 500 men shoulder to shoulder in ninety lines with a front of only 45 yards , moved forward in pre - dawn darkness to attack entrenched Boer positions . Two of the four Highland regiments kept their tight formation with long ropes carried by the left hand man of each file . The result was a rout after nine hours fighting with nearly a quarter of the Scottish soldiers killed or wounded . Military parades . Though of no military value under modern conditions , military parade s up to the present feature soldiers standing and marching in close order formations for ceremonial purposes . Many armies maintain special ceremonial units whose soldiers hold rigorous training in holding such formations - including also in armies established in the Twentieth Century , which themselves have no experience of using such formations on the battlefield .