Hellenistic Armies: Phalanxes, Cavalry and Royal Warfare

Rulers of the Greek successor kingdoms formed after Alexander’s death in 323 BCE recruited pike infantry, hired specialists and maintained cavalry formations. Soldiers could receive land in return for service, linking military recruitment with royal control of territory. Antigonid Macedon, the Seleucid Empire and Ptolemaic Egypt retained the Macedonian phalanx while drawing on different populations.

Their battlefield strength rested on cooperation between several arms. Dense formations of pikemen held or pushed back the enemy, cavalry attacked exposed flanks and pursued retreating troops, while light infantry, elephants and artillery supported the main line. This system could be formidable on suitable ground, but it demanded regular training, reliable supply and commanders capable of keeping separate units coordinated. The large armies of the Hellenistic monarchies were therefore also expressions of royal administration: kings had to recruit soldiers, reward them, feed them and maintain their equipment over long distances.

On this page6 sections

Royal manpower and military settlement

Hellenistic rulers drew soldiers from several sources. Macedonian and Greek citizens remained important, particularly in Macedon and the armies of the successor kingdoms, but Greek settlers were not numerous enough to supply every eastern army. Kings therefore combined citizen troops with local conscripts, allied contingents and mercenaries. The proportion varied by kingdom and period. A Seleucid army could include Macedonian settlers, soldiers from different regions of the empire and contingents from subject or allied peoples. A Ptolemaic army similarly combined Greek and Macedonian soldiers with troops recruited in Egypt.

Mercenaries could form continuing parts of an army rather than a temporary supplement. Leagues and kingdoms combined hired forces with citizen levies and selected units, but their numbers changed with resources and campaigns. Sparta’s declining citizen body also prompted attempts to enlarge recruitment. Cleomenes III connected reforms of citizenship and property with military reorganisation, while hiring and freeing dependent people offered other ways to obtain men and funds.

The Ptolemies and Seleucids granted land to soldiers or veterans, linking holdings with service obligations. Settlements maintained a reserve of men available to royal armies and rewarded service alongside pay.

Pay, booty and royal favour helped sustain loyalty, while land grants and privileged posts could reward service. The cost of campaigning extended to weapons, animals, transport and grain.

The sarissa phalanx and its changing role

The central infantry formation of the Hellenistic armies was the Macedonian-style phalanx. It developed from the Classical Greek hoplite formation under Philip II of Macedon, who made the long sarissa its defining weapon. The sarissa was a two-handed pike whose length varied over time. Descriptions place it at roughly 16 feet in some periods and as much as 22 feet in later development. Because the soldier needed both hands to control it, the phalangite carried a smaller shield suspended from a shoulder harness and forearm support rather than the large round shield of the traditional hoplite.

The front ranks held sarissas horizontally, projecting several rows of points towards the enemy. Men behind raised their pikes, and soldiers could move forward to replace losses. Short swords supplied a secondary weapon. Armour varied by unit and period.

Officers commanded subordinate phalanx blocks. Tactical manuals describe a syntagma of 256 men in sixteen files and sixteen ranks, although armies used differing arrangements. Signals and drills coordinated the movement of these units.

The formation was powerful when it advanced across level ground with secure flanks. Its long weapons made a direct attack against an intact front extremely difficult. Yet the same density that gave the phalanx its strength limited its flexibility. Uneven ground, gaps between units, sudden changes of direction and attacks from the rear or flank could destroy its cohesion.

Different kingdoms recruited and equipped their phalanxes in different ways. Seleucid royal corps included the Argyraspides, or Silver Shields, while Antigonid Macedon relied heavily on its own population. Ptolemaic armies used Greek and Macedonian troops alongside Egyptians and other recruits. At Raphia in 217 BCE, a trained Egyptian phalanx took a major role.

Infantry beyond the pike line

Hellenistic armies needed troops that could operate where a sarissa formation could not. Light infantry used javelins, bows or other missile weapons and could screen the main line, occupy difficult ground and harass an enemy before close combat. Selected troops called peltasts, a name derived from the small pelte shield, could undertake ambushes, forced marches and assaults. The term could describe different kinds of troops, so it does not always identify one uniform unit.

Medium infantry such as thureophoroi and thorakitai offered alternatives to a dense pike block. The oval thureos shield could be used with a spear and missile weapons; more heavily protected troops could also operate in less tightly packed formations.

Antiochus IV displayed 5,000 soldiers equipped in a Roman manner at Daphne in 166 BCE. The extent of a lasting infantry reform remains uncertain. Other medium infantry used oval shields and spears for more mobile fighting.

Cavalry and the protection of the flanks

Armoured cavalry used lances for close action, while lighter riders skirmished with missiles. Troops described as Tarantine were associated with mobile javelin fighting, with the term extending beyond riders from Tarentum.

Antigonid Macedon supplemented native cavalry with hired troops. In 219 BCE, Philip V fielded 400 royal or household horsemen. Seleucid royal cavalry included the Companions and the Agema, which was recruited in the early period from Medes and neighbouring peoples. Ptolemaic cavalry served under hipparchoi and included units named for Thessalians, Thracians, Mysians and Persians; those labels could continue as recruitment changed.

Heavily armoured cavalry, often called cataphracts, reflected eastern traditions as well as royal military adaptation. Seleucid armies employed such troops in the early second century BCE, protecting rider and horse and using long lances for close action. Their effectiveness depended on coordination, terrain and support.

Cavalry was commonly placed on the wings of the army, where it could protect the phalanx, attack enemy horsemen or exploit a break in the opposing line. Its performance could decide a battle even when infantry formed the larger force. Pursuit was dangerous, however. Cavalry that chased a defeated wing too far might be unable to return before enemy elephants or infantry altered the battle elsewhere.

Elephants, artillery and siege forces

Elephants could disrupt enemy horsemen or infantry and provide imposing platforms for armed crews. Their equipment and positioning varied; some carried towers, and commanders could place them on wings or elsewhere in a battle line. Their behaviour was difficult to control under attack. A panicked animal could threaten friendly troops as well as the enemy.

At Raphia in 217 BCE, Antiochus III’s elephants drove back the African elephants of Ptolemy IV. Ptolemy’s phalanx nevertheless defeated the Seleucid centre. An advantage on one wing did not decide the whole engagement.

Mechanical artillery was especially useful in sieges and prepared defensive positions. Transport, ammunition, crews and protection limited its use during a moving field battle.

Most sieges did not depend on continuous bombardment. Attackers might seek surprise, exploit a traitor, rush a weak point or combine patrols and repeated assaults with blockade. Fortified towns required armies to protect their own supply lines while preventing movement in and out of the target.

Strengths and limits of royal warfare

Hellenistic armies could be remarkably large, ranging from a few thousand men to more than 70,000 in particular campaigns. Their size reflected the resources of monarchies that could tax territories, establish settlements and hire soldiers across the eastern Mediterranean and Near East. It also created serious risks. A defeated king might lose the trained manpower needed to rebuild his army, while a smaller state could struggle to replace citizens killed in battle.

Roman forces exploited disrupted pike formations at battles including Cynoscephalae in 197 BCE and Pydna in 168 BCE. Uneven ground and gaps gave legionaries access to troops whose long weapons faced forwards. By 30 BCE, Rome had absorbed the major Mediterranean Hellenistic kingdoms, while other royal states continued farther east.

The defensive works that these forces confronted are explored in Greek fortifications. Greek hoplites explains the earlier citizen-infantry system, while the Hellenistic world places royal armies within the competing kingdoms that financed them.