Philip II of Macedon (359 BC): Building the Macedonian Army

Philip II of Macedon, who ruled from 359 to 336 BC, transformed a small, divided kingdom on the northern edge of the Greek world into the strongest military power in the eastern Mediterranean. His reforms created the Macedonian phalanx armed with the long sarissa pike, supported by heavy cavalry and siege engineers. By the time of his assassination he controlled Greece and had begun the invasion of Persia that his son, Alexander the Great, would complete.

Background: a kingdom in crisis

In the early 4th century BC Macedon was rich in timber, horses and farmland but politically weak. Its kings faced rival claimants, independent highland princes, and raids by Illyrian and Paeonian neighbours, while Athens and Thebes meddled in its affairs.

Philip was born in about 382 BC, the youngest son of King Amyntas III. As a teenager, around 368–365 BC, he lived as a hostage in Thebes, then the leading city in Greece. There he stayed in the house of the general Pammenes and could observe the army of Epaminondas, the victor of the Battle of Leuctra, and its elite Sacred Band.

In 359 BC his brother King Perdiccas III was killed fighting the Illyrians under Bardylis, together with about 4,000 Macedonians. Philip, aged about 23, took control, first possibly as guardian of his infant nephew Amyntas and soon as king.

Securing the throne

Philip faced several rival claimants and invasions at once. He bought off the Paeonians and Thracians with gifts, defeated a pretender backed by Athens, and withdrew his garrison from Amphipolis to keep Athens quiet. In 358 BC he led his rebuilt army against Bardylis and won a crushing victory; Diodorus says about 7,000 Illyrians were killed.

The new Macedonian army

Philip’s reforms are the core of his reputation. Our sources describe them only in part, and historians debate how much was new and how much he built on his predecessors, but the main elements are clear.

• The sarissa phalanx. Infantrymen, the “foot companions” (pezhetairoi), carried a long two-handed pike called the sarissa, usually estimated at about 4.5 to 5.5 metres, with a small shield slung from the neck. In a phalanx about 16 ranks deep, the points of the first several rows projected in front of the line, outreaching Greek hoplite spears.
• The Companion cavalry. Heavy cavalry drawn from the aristocracy, attacking in wedge formations, became the decisive strike force, used together with the phalanx in what historians call the “hammer and anvil”.
• Hypaspists and light troops. More flexible elite infantry and light-armed soldiers protected the flanks and joined the phalanx to the cavalry.
• Training and logistics. Philip drilled his men constantly, ordered long marches with full kit, and cut down baggage trains and servants, making the army faster than its rivals.
• Siege engineering. Under the engineer Polyidus of Thessaly, the Macedonians developed siege towers and torsion artillery.

The army also grew enormously. Diodorus gives Philip about 10,000 infantry and 600 cavalry in 358 BC; at Chaeronea in 338 BC he fielded about 30,000 infantry and 2,000 cavalry.

Expansion and the gold of Pangaion

Philip captured Amphipolis in 357 BC and Pydna and Potidaea soon after. In 356 BC he took over the mining settlement of Crenides near Mount Pangaion and refounded it as Philippi. Diodorus says its gold and silver mines yielded more than 1,000 talents a year, money that paid for professional soldiers, bribes and diplomacy. His gold coins, the philippeioi, circulated widely.

At the siege of Methone in 354 BC an arrow cost him his right eye. In the Third Sacred War (356–346 BC) he intervened in Thessaly, suffered two defeats by the Phocian general Onomarchus in 353 BC, but won the Battle of the Crocus Field in 352 BC and became the effective leader of the Thessalian League. In 348 BC he destroyed Olynthus, the chief city of the Chalcidice.

Diplomacy and Athens

Philip was as skilled at diplomacy as at war. He made peace with Athens in 346 BC (the Peace of Philocrates) and gained a seat on the council that managed the sanctuary of Delphi. He married seven times, mostly for political alliances; his marriage to Olympias of Epirus produced Alexander in 356 BC.

In Athens the orator Demosthenes warned against him in a series of speeches, the Philippics, from 351 BC. In 340 BC Philip besieged Perinthus and Byzantium, threatening Athens’ grain route from the Black Sea; both sieges failed, and Athens declared war.

Chaeronea and the League of Corinth

In 338 BC Athens and Thebes combined against Philip. At the Battle of Chaeronea in August, his army defeated them decisively; the 18-year-old Alexander commanded the cavalry wing. Philip treated Athens leniently but placed a garrison in Thebes.

In 337 BC he summoned the Greek states (except Sparta, which refused) to Corinth and created the League of Corinth, a federation under his leadership. The league declared war on Persia, presented as revenge for the Persian invasions of Greece. In spring 336 BC an advance force under Parmenion and Attalus crossed into Asia Minor.

Court, family and education

Philip’s court at Pella attracted Greek writers, artists and philosophers, part of a long effort by Macedonian kings to present themselves as fully Greek. In 343 BC he invited Aristotle, whose father had been a court physician to Amyntas III, to tutor the teenage Alexander at Mieza.

Philip’s household was also a source of danger. In 337 BC he married Cleopatra, the niece of the Macedonian noble Attalus. At the wedding feast Attalus is said to have prayed for a legitimate heir, an insult to Alexander, whose mother Olympias came from Epirus. Alexander and Olympias left the court for a time, and although father and son were reconciled, tensions over the succession remained when Philip died.

Assassination

In 336 BC, at the old royal capital of Aegae, Philip celebrated the wedding of his daughter Cleopatra to King Alexander of Epirus. As he entered the theatre, he was stabbed by Pausanias of Orestis, a member of his bodyguard. Aristotle and Diodorus describe a personal grievance, but ancient and modern writers have suspected Olympias, Alexander or Persia of involvement. None of these theories can be proved.

Timeline

• c. 382 BC: Philip is born, son of Amyntas III.
• c. 368–365 BC: Philip lives as a hostage in Thebes.
• 359 BC: Perdiccas III is killed; Philip takes power.
• 358 BC: Philip defeats the Illyrians under Bardylis.
• 356 BC: Philippi is founded; Alexander is born.
• 352 BC: Victory at the Crocus Field in Thessaly.
• 348 BC: Olynthus is destroyed.
• 346 BC: Peace of Philocrates with Athens.
• 338 BC, August: Victory at Chaeronea over Athens and Thebes.
• 336 BC: Philip is assassinated at Aegae.

Legacy

Philip’s tomb was long lost. In 1977 the archaeologist Manolis Andronikos excavated rich royal tombs at Vergina, the site of Aegae. Tomb II, with its gold larnax and armour, is often identified as Philip’s, though some scholars argue that he lies in Tomb I and that Tomb II belonged to his son Philip III Arrhidaeus.

Above all, Philip’s achievement made Alexander the Great possible: a loyal, veteran army, a treasury, a network of experienced generals and a ready-made war plan. Ancient writers already debated whether father or son deserved more credit.

Why it matters

Philip II ended the age in which independent Greek cities settled their own affairs and began the era of large Hellenistic kingdoms. His military system dominated warfare in the eastern Mediterranean for more than 150 years, until Roman legions defeated the Macedonian phalanx in the 2nd century BC.