Armies and Infantry: Ancient and Medieval Summary

  • Last updated on November 11, 2022

Infantry is that part or those parts of an army trained and organized to fight on foot with handheld weapons.

Nature and Use

Infantry Infantry;definedInfantry;ancientArmies;ancientis that part or those parts of an army trained and organized to fight on foot with handheld weapons. Foot soldiers have formed the largest component of most armies throughout history. Infantry forces are attested in ancient Mesopotamia, Egypt, Assyria, Greece, Rome, and China, where they were used both in battle and in assaulting and defending fortified positions.Armies;development ofInfantry;development ofArmies;development ofInfantry;development of

Infantry forces were termed either “light” or “heavy,” according to the weapons carried and armor worn by individual foot soldiers. Light Light infantryinfantrymen were equipped with little if any armor, and they used missile weapons such as javelins, bows, and slings to engage the enemy from a distance. Because of their greater mobility, light infantry units were effective in rugged terrain and using guerrilla tactics, but lightly armed soldiers could also be deployed as Skirmishingskirmishers fighting in front of or along the flanks of heavy infantry. Heavy Heavy infantryinfantrymen usually wore heavy defensive armor, carried weapons suited for close combat, such as swords and spears, and fought in dense, compact units. They were most effective in pitched battles fought on open plains.

In loosely organized armies foot soldiers often relied more on numerical superiority than on tactical maneuvering, achieving victory by simply overwhelming enemy forces. Infantrymen were most effective, however, when deployed in organized formations. The Phalanxphalanx and the legion are the best known formations from ancient and medieval times. The phalanx was a square or rectangular formation in which foot soldiers stood shoulder to shoulder in files several ranks deep. When the soldiers of the front line locked their shields together, they presented an impenetrable wall capable of withstanding charges by chariots, cavalry, and even other infantry. On the attack members of a phalanx wielded either thrusting spears or pikes, and a well-disciplined phalanx could overrun many types of opposition. The phalanx was utilized with great success in antiquity by the ancient Greek city-states and the Macedonian Empire. In the fourteenth and fifteenth centuries Swiss pikemen readopted the phalanx to defeat mounted knights.

The Legion (Roman formation)legion was the basic infantry formation of the Roman Armies;Romanarmy. Its size varied over time, but during the third and second centuries b.c.e. it consisted of 4,000 to 5,000 men, mostly heavy infantry. Legionaries wore a helmet and carried a tall body Shieldsshield called the Scutum (shield)scutum. They carried a Javelins Pilum (spear) javelin (pilum) and Swords Gladius (sword) sword (gladius) as close-combat weapons. Unlike the phalanx, the legion did not fight in a single massed formation. Each legion was subdivided into several smaller tactical units usually deployed in three lines that attacked in successive waves. Mobile and flexible, the Roman legion proved to be the preeminent infantry force of the ancient world.


Written records of battles from ancient Egypt and the kingdoms of the Middle East frequently mention infantry, but it is difficult to determine what role foot Foot soldierssoldiers played and how important they were in combat. The Sumerians;infantrySumerian Stela of the Vultures, dating from about 2500 b.c.e., depicts spearmen in a phalanx-like formation, but during the second millennium b.c.e. infantry may have fought primarily as skirmishers in support of chariots. One theory holds that the foot soldiers rose in prominence only around 1200 b.c.e., when “barbarian” tribes, fighting on foot and armed with javelins and long swords, overran many of the kingdoms of the ancient Middle East. A similar transition away from chariot warfare to infantry began to occur in China in the fifth century b.c.e.

The Assyrians;infantryAssyrians organized their infantry into specialized units in the early first millennium b.c.e., but the armies of the ancient Greece;infantryGreek city-states were the first to rely almost exclusively on soldiers fighting on foot. Around 700 b.c.e. they began to deploy infantrymen called Hopliteshoplites in densely packed phalanxes. Each hoplite wore a bronze helmet, corselet, and greaves, or shin guards. He carried a circular shield for protection and used a thrusting spear as his primary weapon. The phalanx was suited to the small plains of Greece, and in battle it attacked in tight formation. As they neared the enemy, hoplites in the front ranks of the phalanx raised their shields and spears and jabbed at their opponents, while those in the rear pushed on the backs of those ahead of them. Hoplite battles resembled shoving matches, as a phalanx sought to overwhelm its opponent by its momentum. The success of the phalanx ultimately depended on the cohesion of its members.

The superiority of the Greece;infantryAthens;infantrySparta;infantryGreek hoplite army was demonstrated first at the Battle of Marathon, Battle of (490 b.c.e.)Marathon (490 b.c.e.), where the Athenian hoplite phalanx charged and defeated a numerically superior but more lightly armed Persian force. A second Persian campaign against Greece met a similar fate during the Greco-Persian Wars (499-448 Greco-Persian Wars (499-448 b.c.e.)[Greco Persian Wars]b.c.e.). Spartan hoplites held the narrow pass of Thermopylae, Battle of (480 b.c.e.)Thermopylae (480 b.c.e.) for several days against vastly superior Persian numbers, and at Plataea (479 Plataea, Battle of (479 b.c.e.)b.c.e.) a hoplite army drawn from Sparta, Athens, and other Greek city-states defeated the Persians decisively. Greek hoplites remained the elite warriors of the Mediterranean world for nearly a century and a half.

The prominence of infantry battle in Greek warfare declined somewhat during the Peloponnesian Wars (431-404Peloponnesian War (431-404 b.c.e.)b.c.e.), which pitted the naval strength of Athens against the land-based power of Sparta. Few infantry battles were fought, and the war was ultimately decided at sea. Decisive hoplite battles did take place during the fourth century b.c.e., but new developments changed the face of Greek warfare. At Lechaeum (390 Lechaeum, Battle of (390 b.c.e.)b.c.e.), on the Gulf of Corinth, a force of Peltastspeltasts, light infantry armed with javelins, decimated a Spartan regiment and illustrated the vulnerability of heavy infantry to light-armed troops. At Leuctra (371 Leuctra, Battle of (371 b.c.e.)b.c.e.) the Theban commander EpaminondasEpaminondas (Theban commander)Epaminondas (c. 410-362 b.c.e.) employed novel tactics to defeat the Spartan phalanx. Epaminondas strengthened the left wing of the Theban phalanx to a depth of fifty men and charged the Spartans at an oblique angle. The weight of the Theban left flank ripped through the Spartan line, and the supremacy of the Spartan hoplite was ended forever.

A Greek hoplite, circa 700 b.c.e., wearing a bronze helmet, corselet, and shin guards, and carrying a circular shield and a thrusting spear.

(Kimberly L. Dawson Kurnizki)

More significant were the innovations of Philip II of MacedonPhilip II of Macedon (382-336 b.c.e.), who reformed the Macedonian army, including its infantry. Philip increased the depth of the Macedonian phalanx and reduced the size of the shield carried by its members. He also armed his infantry with Sarissa (pike)sarissas, pikes nearly 15 feet in length and, unlike the spears of the Greek hoplites, wielded with two hands. At Chaeronea (338 Chaeronea, Battle of (338 b.c.e.)b.c.e.) Philip combined the new Macedonian phalanx with his cavalry to rout a hoplite army of Thebans and Athenians. Philip’s son, Alexander the GreatAlexander the Alexander the Great;strategiesGreat (356-323 b.c.e.), employed similar combinations of infantry and cavalry charges at Granicus (334 Granicus, Battle of (334 b.c.e.)b.c.e.), Issus (333 Issus, Battle of (333 b.c.e.)b.c.e.), and Gaugamela (331 Gaugamela, Battle of (331 b.c.e.)b.c.e.) to break the Persian army and conquer the Persian Empire. The size of the Macedonian phalanx grew in the armies of the Hellenistic kingdoms founded after Alexander’s death, but infantry was increasingly used in conjunction with other forces, including chariots and elephants.

As the Greeks and Macedonians employed phalanx tactics, the Rome;infantryRomans developed a style of infantry warfare based on the Legion (Roman formation)legion. The legion evolved over the course of the Roman conquest of Italy in the fifth and fourth centuries b.c.e. Its heavy infantrymen were deployed in three lines, each made up of ten units called Maniple (Roman unit)maniples. In battle the first line of maniples, the Hastati (Roman army unit)hastati, advanced first. When they neared the enemy they released their javelins and then drew their swords and charged, seeking to take advantage of the confusion caused by their missiles. If the hastati failed to defeat the enemy, they were joined by the second line of maniples, the Principe (Roman army unit) principes, which used similar tactics. The third line of maniples, the Triari (Roman army unit) triarii, were armed as spearmen, and they engaged only when the situation became critical.

With their legionary tactics, the Romans overcame the peoples of Italy and the western Mediterranean. Roman legions, however, were not invincible, and the Roman infantry met defeat in battles against Pyrrhus and in the Second Punic Punic War, Second (218-201 b.c.e.)War (219-202 b.c.e.) against the Carthaginian general Hannibal BarcaHannibal BarcaHannibal (247-182 b.c.e.). The Romans were able to draw on enormous reserves of manpower to replenish their losses, and they learned from their defeats. They lost battles but won wars. In the second century b.c.e. the experience gained by decades of fighting in Italy helped Roman infantrymen defeat the Macedonian phalanx in the Second and Third Macedonian-Roman Wars (200-196 b.c.e., 172-167 b.c.e.). Thus, although the Macedonian phalanx initially carried all before it at the Battle of Pydna, Battle of (168 b.c.e.)Pydna (168 b.c.e.), it lost cohesion as it advanced, allowing Roman legionaries to pour into gaps in its line and cut down the Macedonians at close range with their swords.

The Roman legion underwent further reforms during the second century b.c.e., and by the time of the general Gaius Marius, GaiusMarius, GaiusMarius (157-86 b.c.e.) ten cohorts had replaced the thirty maniples as the legion’s tactical units. With the change to Cohort (military unit)cohorts the distinctions between hastati, principes, and triarii disappeared, so that all legionaries were armed and fought in the same fashion. The legion continued to deploy for battle in three lines, with four cohorts in the first line and three cohorts in the second and third, but this arrangement could be varied, and unlike maniples, individual cohorts could operate independently. Julius Caesar, JuliusCaesar, JuliusCaesar (100-44 b.c.e.) employed cohorts very effectively in the Gallic Wars (58-51 Gallic Wars (58-52 b.c.e.)b.c.e.) and in the Roman Civil Wars (88-30 b.c.e.)Roman Civil Wars against Pompey the GreatPompey (49-45 b.c.e.).

Under the Roman Republic, the infantry of Rome’s legions was an offensive force. With the establishment of the Empire, Roman infantry forces acquired a defensive role. Rome’s legions manned the frontiers of the Roman Empire and engaged in few pitched battles in the first few centuries c.e. The size of the legion decreased, and legionaries discarded their heavy armor and adopted missile weapons. Cavalry;RomanRome;cavalryCavalry acquired a more important role in Rome’s armies as a result of barbarian incursions across the Empire’s borders during the third and fourth centuries c.e. Infantry remained the dominant component of the legion into the fourth and fifth centuries c.e., and in pitched battle Roman foot soldiers were vastly superior to their barbarian counterparts, as demonstrated in 357 c.e., for example, at Strasbourg, then called Argentoratum. Even the defeat of the Roman army at Adrianople, Battle of (378 c.e.)Adrianople (378 c.e.) was due largely to the flight of the Roman cavalry, not to the weakness of its infantry. After that point, however, foot soldiers became increasingly dependent on mounted soldiers, and cavalry gradually assumed a more decisive role.

The millennium following the fall of the Roman Empire is sometimes labeled an age of Cavalry;age ofInfantry;medievalArmies;medievalcavalry. Although cavalry charges often determined the outcome of battle, it would be a mistake to discount altogether the importance of foot soldiers in this period. Frankish armies fought on foot well into the time of Charlemagne (742-814 c.e.), and Anglo-Saxon armies in England relied on foot soldiers up until the Battle of Hastings (1066 c.e.). Well-disciplined infantry could also withstand a charge of mounted knights, as did the Milanese at Legnano (1176 c.e.). Something of an infantry revolution, however, took place in the fourteenth century, spurred in part by the greater use of the pike and bow. At Courtrai (1302 Courtrai, Battle of (1302)c.e.) Flemish infantry, armed with pikes, withstood a charge of French cavalry and then slaughtered the knights who had fallen from their mounts. In 1314 English cavalry suffered a similar fate against the Scottish pikemen at Bannockburn, Battle of (1314)Bannockburn. Use of the Crossbowscrossbow, capable of piercing the armor of a mounted knight, had also begun to challenge the supremacy of cavalry during the twelfth century, but the longbow proved more effective in terms of cost, rate of fire, range, and accuracy. By the late thirteenth century a majority of English foot soldiers carried the Longbowslongbow, and their large numbers proved decisive against the Scots at Falkirk Falkirk, Battle of (1298)(1298), and later in the Hundred Years’ War Hundred Years’ War (1337-1453)(1337-1453) against the French at Crécy Crécy, Battle of (1346)[Crecy, Battle of](1346), Poitiers Poitiers, Battle of (1356)(1356), and Agincourt Agincourt, Battle of (1415)(1415).

The most significant infantry innovation was the development of the Swiss Phalanx;SwissSwiss phalanxphalanx. Swiss infantrymen wore little armor and carried no shields, but they carried either a Pikemen;Swisspike 18 feet in length or a Halberdshalberd, both of which were wielded with deadly effect. After infantrymen in the outer ranks of the phalanx delivered the initial blows with their pikes, soldiers armed with halberds emerged from the phalanx and engaged enemy cavalry and foot soldiers at close quarters. When harassed on all sides by cavalry, the Swiss phalanx could also adopt a “hedgehog” formation, with pikes turned outward in all directions. A string of Swiss victories over mounted knights began early in the fourteenth century at Morgarten Morgarten, Battle of (1315)(1315) and by

the end of the fifteenth century, European monarchs were either recruiting Swiss infantrymen into their armies or modeling their own infantry units after the Swiss. Infantry had again come to dominate Western warfare.Armies;development ofInfantry;development of

Books and Articles
  • Darnell, John Coleman, and Colleen Manassa. Tutankhamun’s Armies: Battle and Conquest During Ancient Egypt’s Late Eighteenth Dynasty. Hoboken, N.J.: John Wiley and Sons, 2007.
  • Dawson, Doyne. The First Armies. London: Cassell, 2001.
  • DeVries, Kelly. Infantry Warfare in the Early Fourteenth Century: Discipline, Tactics, and Technology. Woodbridge, England: Boydell Press, 1996.
  • Drews, Robert. The End of the Bronze Age: Changes in Warfare and the Catastrophe c. 1200 B.C. Princeton, N.J.: Princeton University Press, 1993.
  • Gabriel, Richard A. The Great Armies of Antiquity. Westport, Conn.: Praeger, 2002.
  • Gush, George. Renaissance Armies, 1480-1650. Cambridge: P. Stephens, 1982.
  • Hanson, Victor. The Western Way of War: Infantry Battle in Classical Greece. 2d ed. Berkeley: University of California Press, 2000.
  • Head, Duncan. Armies of the Macedonian and Punic Wars, 359 B.C. to 146 B.C.: Organisation, Tactics, Dress, and Weapons. Drawings by Ian Heath. Goring-by-Sea, West Sussex, England: Wargames Research Group, 1982.
  • Heath, Ian. Armies of the Middle Ages: Organisation, Tactics, Dress, and Weapons. Goring-by-Sea, West Sussex, England: Wargames Research Group, 1982.
  • Katcher, Philip R. N. Armies of the American Wars, 1753-1815. New York: Hastings House, 1975.
  • Lepage, Jean-Denis. Medieval Armies and Weapons in Western Europe: An Illustrated History. Jefferson, N.C.: McFarland, 2005.
  • Marshall, Christopher. Warfare in the Latin East, 1192-1291. New York: Cambridge University Press, 1992.
  • Prestwich, Michael. Armies and Warfare in the Middle Ages: The English Experience. New Haven, Conn.: Yale University Press, 1996.
  • Sage, Michael M. The Republican Roman Army: A Sourcebook. New York: Routledge, 2008.
  • Santosuosso, Antonio. Soldiers, Citizens, and the Symbols of War: From Classical Greece to Republican Rome, 500-167 B.C. Boulder, Colo.: Westview Press, 1997.
  • Wise, Terence. Armies of the Crusades. Color plates by G. A. Embleton. Botley, Oxford, England: Osprey, 1978.
Films and Other Media
  • Henry V. Feature film. BBC/Curzon/Renaissance, 1989.
  • In Search of History: The Roman Legions. Documentary. History Channel, 1996.
  • Modern Marvels: Battle Gear. Documentary. History Channel, 2008.
  • Weapons at War: Infantry. Documentary. History Channel, 1992.

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