How Philip II’s Reforms Revolutionised Ancient Warfare | History Hit

How Philip II’s Reforms Revolutionised Ancient Warfare

Victory medallion bearing effigy of Philip II of Macedon.
Image Credit: Public Domain

In 359 BC, the Kingdom of Macedonia (northern Greece today) was in crisis. Having suffered a catastrophic recent defeat in which their king had perished and army had disintegrated, this Kingdom appeared on the brink of ruin.

However, into this crisis a new king stepped, whose reforms would completely transform Macedonian fortunes. He would turn Macedon from a kingdom on the brink of ruin into the dominant power in mainland Greece within the space of 20 years. This was King Philip II, the father of Alexander the Great.

At the heart of Macedon’s rise under Philip were a series of extraordinary military reforms – covering logistics, siege machinery, cavalry and infantry. This article will explore the massive reforms he made to the infantry, introducing a new style of warfare that went on to conquer large swathes of the known world: the Macedonian phalanx.

Philip II learned from other Greeks

Philip did not spend much of his youth in his native Macedonia. Instead, thanks to the fragility of the kingdom, the young prince served as a hostage of foreign powers: first at the court of the Illyrians and then at Thebes. It was while residing at the latter that Philip’s ideas of radical military reform likely took root.

In 371 BC, the balance of power between the mainland Greek cities was shaken to its core. At Leuctra, the Thebans won a stunning victory against the Spartans, replacing them as the dominant power on the Greek mainland. The reason behind this unprecedented victory was the military innovation and expert leadership of two leading citizens, Epaminondas and Pelopidas.

Most notable among the Theban innovations were those that radically improved the Theban infantry. Not only had Epaminondas’ decided to concentrate his Theban hoplite phalanx in deeper ranks on the left of his line, which resulted in the shattering of opposing Spartans. He also created an elite, professional infantry body, the Sacred Band. They provided Thebes with a force that proved equal to the famed Spartan warriors of antiquity.

In Thebes at the time of Leuctra, Philip appreciated that the secret of Thebes’ military supremacy was its professionalism. At the same time, the reforms of another leading Greek general also appear to have greatly impressed the young Macedonian. His name was Iphicrates.


A renowned Athenian general, Iphicrates had recently experimented with reforming the weaponry of some of the Athenian infantry. He had replaced the heavier bronze hoplite armour with lighter linen cuirasses and the large, circular hoplon shield with a lighter, smaller equivalent, the pelta. He had also equipped these men with much longer spears. The increased length of this new spear meant that it had to be held with both hands, while the reduced body armour provided the soldiers with increased mobility.

These reforms did not stand the test of time with the Athenian infantry. Yet scholars assume that this style of fighting continued for those hoplites that were fighting on ships at sea – the increased spear-length and improved flexibility undoubtedly proving very useful when attacking adjacent enemy vessels. Reform and military innovation was therefore a common theme among the mainland Greeks in the early 4th century BC.

‘The Acropolis from the West, with the Propylaea and the Temple of Athena Nike, Athens’, Thomas Hartley Cromek, 1834.

Image Credit: The Metropolitan Museum of Art

Returning home

In 365 BC, Philip returned to Macedonia. The death of Philip’s elder brother Perdiccas, in a battle against the Illyrians in 359 BC, brought Philip an abrupt ascension to the Macedonian throne. The kingdom he inherited had never been weaker. With potential enemies to his north, east and west, Philip’s tenure as king was by no means guaranteed. Another invasion looked imminent.

Having secured his throne from rival claimants, he set about reforming the Macedonian army, putting into practice what he had learnt from Epaminondas, Pelopidas and Iphicrates  while a hostage.

How did Philip the II reorganize his army?

Arguably the factor Philip most revolutionised was the infantry. Although limited evidence survives, it is likely that in 359 BC Philip’s foot soldiers were of a very poor quality. Scholars presume they had mostly been light infantry, recruited from a peasant class deep in poverty, usually ill-equipped and lacking training. Consequently, they had proven no match for the superior infantry of their neighbours, including the Illyrians. Though it appears the Macedonians also maintained an elite unit, armed in the Greek hoplite fashion, these hoplites were few in number and no match for their Illyrian counterparts.

Philip saw the need for change. He quickly recruited 4,000 Macedonian levies and equipped them for a radical new style of fighting. For their armour, Philip equipped his Macedonians with a blend of the heavy hoplite and the lighter Greek peltast panoply. Each soldier was fitted with a bronze helmet, greaves, tall boots and a cloth tunic. Unlike the southern hoplites, Philip did not arm his new recruits with heavy breastplates, but much lighter body armour. This was a compromise made up for by a new weapon that Philip developed: the sarissa.

The sarissa

Their deadly new armament was a 4-6-metre-long pike. Its shaft was made from cornel wood – the best available wood in the Greek world at that time. Fortunately for Philip, Macedonia was renowned for such high-quality timber. He thus acquired significant supplies to create his new weapon.

At one end of the sarissa was an iron pike tip. Its streamlined head was designed specially to penetrate armour and continue through into the enemy’s body. Meanwhile, at the opposite end of the pike was a heavy metal butt. Made of either iron or bronze, this butt was designed to act as a counterweight, offering the wielder more balance when holding the sarissa three quarters of the way down the shaft. Its shape also anchored the pike into the ground when bracing for an enemy charge.

Just as with the high-quality cornel wood, bronze and iron were also readily available in Macedonia. Philip thus had easy access to the materials required for these new deadly weapons.

The Macedonian phalanx, from “Cassell’s Illustrated Universal History” (1893).

Image Credit: British Library / Public Domain

The pelta

Unlike the shorter doru spears of the hoplites, the sheer length and weight of the sarissa meant that each Macedonian soldier required both hands to carry it. Carrying a heavy shield as well was impossible. Philip therefore equipped his men with a smaller, light shield called a pelta.

The Pelta was commonly used by the Greek light infantry and by Iphicrates’ new-look Athenians earlier in the 4th century. An infantryman could sling it around his neck and strap it to his left arm. These men were also equipped with a short spear and a slashing sword, but the pike was the primary weapon.

Equipped in such a manner, Philip did not intend for these pikemen to fight on their own; the sarissa was next to useless in a one-on-one fight. Instead, Philip intended each man should fight as part of a larger, trained mass: the Macedonian phalanx.

How did Philip II change the phalanx?

Originally, the Macedonian phalanx consisted of basic units of ten men called a dekas, although this number was soon increased to 16. Multiple dekas units, or dekades, combined into larger groupings called a lochos (lochoi in the plural). They deployed the separate dekades side by side and placed the most experienced men nearer the front.

At its beginning, it appears the Macedonian phalanx was primarily trained to be formed 16-men deep and 8-men across – the men being in very close order thanks to the small size of their shields. This basic tactical unit consisted of 128 men and was commanded by an officer called a lochagos.

Alongside the lochagos, other specialised soldiers also served alongside each lochos. There was the bugler – the salpingetes – who would relay messages with his bugle during the heat of battle. There was also a signalman – called the semeiphoros – who would give visual signals during the march with his standard, as well as an army herald – a stratokerux – who would shout out orders.

There was also an aide – a hyperetes – who was to convey messages between units and do whatever the lochagos required, and finally a file closer – the ouragos – who would collect any stragglers from the phalanx.

Wall of iron

As each lochos moved in their rectangular formation on the battlefield, every man would carry their sarissa upright. Only just before they were to engage their enemy would the first five ranks lower their deadly pikes horizontally, creating a deadly wall of iron. The lines just behind would lower their own pikes at a 45-degree angle to protect their comrades from enemy projectiles. The rows further back would keep their pikes upright.

Thanks to the great length of the pike, four deadly sarissa heads could protrude ahead of the first infantryman in the phalanx. Not only could the sheer offensive power of multiple advancing sarissae steamroll any opponent, but any opposing infantry force would struggle to get past the multiple rows of pikes to even reach the holder, becoming pinned on a line of deadly iron tips.

From the elite hoplite infantry of both the Illyrians and the Greeks to the hardened warriors of Thrace and Paeonia, all would struggle to combat Philip’s sarissa-wielding phalanx with their shorter spears.

The Battle of Chaeronea August 338 BC.

Image Credit: Public Domain

Flaws of the Macedonian phalanx

Taken from the front, Philip’s new Macedonian phalanx was virtually unstoppable. Its cohesiveness and the weight of its offensive armament was unmatched in the contemporary world. Yet this new formation was not without its flaws.

The key to the phalanx’ deadliness was its cohesiveness. If the formation was shattered – whether it be from fighting on uneven ground or from being attacked on either the side or rear – then the poor individual fighting skill of these soldiers would soon be apparent. The phalanx was deadly just for so long as it maintained its order.

And so, in 359 BC, Philip equipped and trained his 4,000 new Macedonian recruits in this new, revolutionised system of warfare. Continuously he would train them in a variety of manoeuvres to make sure they were ready for war.

He ensured the phalanx formation had flexibility for example, training his men to either double or halve the usual 16-man depth of the phalanx when necessary. Furthermore, Philip also made his infantry march and run long distances with full equipment so that they were always fit and ready for battle when on campaign.

The Pezhetairoi

As we have mentioned, the majority of Philip’s reformed infantrymen originated from the Macedonian levy of the region – farmers, craftsmen and men from other citizen professions. But Philip also had an elite corps: the pezhetairoi or ‘foot companions’.

These men were a force selected for their size and strength from the infantry, and served as the king’s distinguished guard. The pezhetairoi were also Philip’s only professional soldiers, far out-classing the skill of the rest of his infantry. Truly they were the Macedonian equivalent of the famed Theban Sacred Band.

Philip stationed his elite pezhetairoi on the furthest right wing of the infantry line – the most prestigious place among the footmen in his army. It was the pezhetairoi for example, that probably accompanied Philip on his right during his first major battle in 357 BC against the Illyrians.

Leading his best soldiers forwards ahead of the rest of his army, we hear that Philip and his elite phalanx shattered the opposing Illyrians, who proved no match for them. For the first time in years, the Macedonian infantry outclassed its neighbours.

Elite forces of ancient Greece

Scholars still debate the equipment of Philip’s pezhetairoi. Some argue these men were armed as hoplites, wielding shorter spears, a larger, aspis, shield and heavy, bronze body armour, trained to add versatility to Philip’s sarissa-wielding infantry line.

Yet surviving evidence for this assumption is sparse. Many instead argue that Philip equipped his pezhetairoi with the same equipment as the rest of his reformed infantry. It was their skill and expertise with not just the sarissa, but also the spear and sword, that singled these soldiers from the rest, not their equipment.

Later, upon the accession of Philip’s son, Alexander, this elite infantry force would undergo a significant change. Alexander extended the name pezhetairoi to include the entirety of his phalanx. He thus gave his elite infantry a new name, which would endure through the Hellenistic period: the hypaspists.

Reforming the Macedonian infantry was just part of Philip’s great plan. He also reformed the cavalry and siege equipment. But Philip’s infantry reforms were the first great step in transforming his kingdom from the brink of destruction towards ascendance in the Central Mediterranean.

Tags: Philip II of Macedon

Tristan Hughes