The Macedonian army was the army of Macedon under the leadership of Philip II and Alexander the Great. Macedonian army became noted for its speed of movement and proficiency in combat as one of the most effective and successful armies in the ancient world during the Rise of Macedon under Philip II and the campaigns of Alexander. After gaining an ascendancy in Greece the army was instrumental in the conquest of large swathes of territory stretching from Egypt in the west to India in the east. Initially of little account in the Greek world, Macedon was widely regarded as a second-rate power before being made formidable by Philip II, whose son and successor, Alexander the Great, conquered the Achaemenid Empire in just over a decade.
The latest innovations in weapons and tactics were adopted and refined by Philip, and he created a uniquely flexible and effective army. By introducing military service as a full-time occupation, Philip was able to drill his men regularly, ensuring unity and cohesion in his ranks. In a remarkably short time, this led to the development of one of what was among the world's finest military machines for the era. Tactical improvements included the latest developments in the deployment of the traditional Greek phalanx made by men like Epaminondas of Thebes and Iphicrates of Athens. Philip improved on these military innovators by using both Epaminondas' deeper phalanx and Iphicrates' combination of a longer spear and a smaller and lighter shield. However, the Macedonian king also innovated; he introduced the use of a much longer spear, the two-handed pike. The Macedonian pike, also known as the sarissa, gave its wielder many advantages both offensively and defensively. For the first time in Greek warfare, cavalry became a decisive arm in battle. The Macedonian army perfected the co-ordination of different troop types in an early example of combined arms tactics—the heavy infantry phalanx, skirmish infantry, archers, light cavalry and heavy cavalry, and siege engines were all deployed in battle; each troop type being used to its own particular advantage and creating a synergy of mutual support.
Ancient Macedonians and other Greeks (especially Thessalian cavalry) and a wide range of mercenaries from across the Aegean and the Balkans were employed by Phillip. By 338 BC, more than a half of the army for his planned invasion of the Achaemenid Empire came from outside of Macedon's borders—from all over the Greek world and the nearby barbarian tribes, such as the Illyrians, the Paeonians, and the Thracians.
As a result of uneven manuscript survival, most of the primary historical sources for this period have been lost, and scholarship is thus largely reliant on the works of the Greek historians Diodorus Siculus and Arrian, in addition to the incomplete writings of the Roman historian Curtius, all of whom lived centuries later than the events they describe in their works.
If Philip II of Macedon had not been the father of Alexander the Great, he would be more widely known as a first-rate military innovator, tactician and strategist, and as a consummate politician. The conquests of Alexander would have been impossible without the army his father created. Considered semi-barbarous by some metropolitan Greeks, the Macedonians were a martial people; they drank deeply of unwatered wine (the very mark of a barbarian) and no youth was considered to be fit to sit with the men at table until he had killed, on foot with a spear, a wild boar.
When Philip took over control of Macedon, it was a backward state on the fringes of the Greek world and was beset by its traditional enemies: Illyrians, Paeonians and Thracians. The basic structure of the army inherited by Philip II was the division of the companion cavalry (hetairoi) from the foot companions (pezhetairoi), augmented by various allied troops, foreign levied soldiers, and mercenaries. The foot companions existed perhaps since the reign of Alexander I of Macedon, while Macedonian troops are accounted for in the history of Herodotus as subjects of the Persian Empire fighting the Greeks at the Battle of Plataea in 479 BC. Macedonian cavalry, wearing muscled cuirasses, became renowned in Greece during and after their involvement in the Peloponnesian War (431–404 BC), at times siding with either Athens or Sparta and supplemented by local Greek infantry instead of relying on Macedonian infantry. Macedonian infantry in this period consisted of poorly trained shepherds and farmers, while the cavalry was composed of noblemen eager to win glory. An early 4th-century BC stone-carved relief from Pella shows a Macedonian hoplite infantryman wearing a pilos helmet and wielding a short sword showing a pronounced Spartan influence on the Macedonian army before Philip II.
Nicholas Sekunda states that at the beginning of Philip II's reign in 359 BC, the Macedonian army consisted of 10,000 infantry and 600 cavalry, the latter figure similar to that recorded for the 5th century BC. However, Malcolm Errington cautions that any figures for Macedonian troop sizes provided by ancient authors should be treated with a degree of skepticism, since there are very few means by which modern historians are capable of confirming their veracity (and could have been possibly lower or even higher than the numbers stated).
Philip's first achievement was to unify Macedon through his army. He raised troops and made his army the single fount of wealth, honour and power in the land; the unruly chieftains of Macedonia became the officers and elite cavalrymen of the army, the highland peasants became the footsoldiers. Philip took pains to keep them always under arms and either fighting or drilling. Manoeuvres and drills were made into competitive events, and the truculent Macedonians vied with each other to excel.
As a political counterbalance to the native-born Macedonian nobility, Philip invited military families from throughout Greece to settle on lands he had conquered or confiscated from his enemies, these 'personal clients' then also served as army officers or in the Companion cavalry. After taking control of the gold-rich mines of Mount Pangaeus, and the city of Amphipolis that dominated the region, he obtained the wealth to support a large army. It was a professional army imbued with a national spirit, an unusual combination for the Greek world of the time. The armies of contemporary Greek states were largely reliant on a combination of citizens and mercenaries. The former were not full-time soldiers, and the latter, though professional, had little or no inherent loyalty to their employers. By the time of his death, Philip's army had pushed the Macedonian frontier into southern Illyria, conquered the Paeonians and Thracians, asserted a hegemony over Thessaly, destroyed the power of Phocis and defeated and humbled Athens and Thebes. All the states of Greece, with the exception of Sparta, Epirus and Crete, had become subservient allies of Macedon (League of Corinth) and Philip was laying the foundations of an invasion of the Persian Empire, an invasion that his son (Alexander the Great) would successfully undertake.
One important military innovation of Philip II is often overlooked, he banned the use of wheeled transport and limited the number of camp servants to one to every ten infantrymen and one each for the cavalry. This reform made the baggage train of the army very small for its size and improved its speed of march.
Troop types and unit organisation
The Companion cavalry, or Hetairoi (Ἑταῖροι), were the elite arm of the Macedonian army, and were the offensive force that made the decisive attack in most of the battles of Alexander the Great. They were unmatched in the pre-stirrup Ancient world in their ability to retain their seat and the control of their weapons through the impact of a charge. Along with Thessalian cavalry contingents, the Companions – raised from landed nobility – made up the bulk of the Macedonian heavy cavalry. Central Macedonia was good horse-rearing country and cavalry was prominent in Macedonian armies from early times. However, it was the reforms in organisation, drill and tactics introduced by Philip II that transformed the Companion cavalry into a battle-winning force, especially the introduction of, or increased emphasis on, the use of a lance and shock tactics. Coinage indicates that from an early period the primary weapons used by Macedonian cavalry were a pair of javelins. This remained true through to the reign of Archelaus I (413–399). Subsequently, despite the adoption of the lance, it is highly probable that the Companion cavalry continued to employ javelins when on scouting or skirmishing missions.