In 168 BCE, the Roman legions delivered a crushing defeat to the kingdom of Macedonia. The Battle of Pydna marked the end of Macedonia’s reign in just one day.
The Battle of Pydna was the second significant showdown between the Macedonian phalanx and the Roman legion. The first encounter at Cynoscephalae in 197 BCE saw the Romans outsmarting and defeating the Macedonians, leading to Macedonia losing its long-standing grip on Greece. However, the kingdom managed to survive for another fight, which took place on June 22, 168 BCE, when the Macedonian and Roman armies met again, this time with the very survival of Macedonia on the line.
What Sparked the Third Macedonian War
There wasn’t a single event that triggered the Third Macedonian War (171-168 BCE); rather, it grew from Rome’s mistrust of Macedonia and its king, Perseus (179-168 BCE), whom they viewed as a potential threat to their power in the eastern Mediterranean.
Most accounts paint Perseus in a pretty negative light, but some of this may be just propaganda meant to justify Rome’s military actions. If we take the sources at face value, Perseus comes off as sneaky, cowardly, war-hungry, stingy, and even responsible for his brother’s murder. Some Romans were suspicious of him even before he took the throne because he was blamed for the death of his popular brother Demetrius.
Later Roman historians claimed that Perseus inherited a dislike for Rome and war plans from his dad. In reality, one of his first moves was to keep peace, and he often communicated with the Roman senate, even trying to negotiate during the war on multiple occasions. Both Philip V (221-179 BCE) and Perseus did work on rebuilding the Macedonian army, but this seems more like common sense than a war strategy.
As part of the rebuilding effort, Perseus sought to mend relationships with various Greek states and form alliances with Bithynia in Asia Minor and the Seleucids in Syria. His diplomatic moves beyond Macedonia were cautious and initially went unnoticed by the Romans. Still, there was probably some anxiety that a revitalized Macedonia could disrupt the balance set up after the Second Macedonian War (202-197 BCE).
In this climate of suspicion, it didn’t take much for Rome to find an excuse for war. Eumenes II of Pergamon (197-159 BCE), a Roman ally, played on Roman fears, claiming that Perseus posed a threat and might invade Italy. The Senate bought into these tales, especially when Eumenes alleged that Perseus had tried to have him assassinated near Delphi, giving them the green light to wage war. After twenty-five years of shaky peace, Rome prepared to send its legions back to Macedonia.
The Third Macedonian War
As the Romans geared up for conflict in 172-171 BCE, Perseus found himself largely isolated with few allies. His attempts to rebuild ties with southern Greek states failed due to their fear of Roman retaliation and lingering bitterness over Macedonia’s prior dominance. Only parts of the Boiotian communities in central Greece were willing to support him. To the north and west, there were hopes of winning over Epirus and Illyria, but any allies there would threaten Rome’s ability to send troops and supplies.
With little external support, Perseus had to rely on his own forces. Thanks to the careful preparation done by Philip V and Perseus, there was some hope as the Macedonian army was said to number over 40,000 soldiers, possibly its strongest since the days of Philip II and Alexander the Great nearly 200 years ago.
At the heart of this force was the renowned Macedonian heavy infantry phalanx. This formation featured tightly packed pikemen wielding an 18-foot spear called a sarissa. The length of the sarissa allowed multiple spear points to protrude, creating a wall of spears against the enemy. Massed in formations up to sixteen soldiers deep, the phalanx was nearly impossible to penetrate once it got moving. This tactic had helped conquer the Persian Empire and sustain the Hellenistic kingdoms, but the Romans had previously bested the phalanx at Cynoscephalae by leveraging their legions’ greater flexibility.
Macedonia’s preparations seemed fruitful at the start of the war, as Perseus triumphed over a Roman contingent at the Battle of Callinicus in 171 BCE and gained ground in Epirus and Illyria. Roman attempts to invade Macedonia faltered, but these early victories were inconclusive. Perseus probably hoped that if he could avoid defeat, the Romans might eventually lose interest in the war and settle for a negotiated peace—something he tried to achieve several times without success. As with his father’s conflict, the resolution hinged on a decisive battle between the phalanx and the legion.
Campaign of 168 BCE
In 169 BCE, the war reached Macedonia as Roman forces crossed Mt Olympus. However, once they were over the mountains, their campaign stalled. Perseus reportedly panicked upon hearing this news and missed the chance to confront his weary adversaries as they emerged from the grueling trek. The Romans, having arrived in Macedonia, lacked supplies, resulting in a stalemate. Perseus fortified his position along the river Elpeus, creating a narrow barrier between the mountains and the sea to block further Roman advances.
Due to the underwhelming performance of the legions, Lucius Aemilius Paullus was elected consul and put in command in Macedonia for 168 BCE. At 60 years old and coming from a family of generals, he was seen as the man to revitalize the Roman war effort. Once he arrived at the front in early summer 168 BCE, he reestablished discipline and looked for a way to bring about a decisive confrontation.
Paullus faced a challenge, though; Perseus’ strong defensive stance along the river was tough to break through. However, the Romans controlled the seas surrounding Macedonia. Fearing a Roman landing along the coast, Perseus pulled several thousand troops from his army, leaving his forces weaker against Paullus. Even with this advantage, the Roman leaders took an unexpected route. A small Roman unit pretended to march toward the coast to outflank the Macedonian position by sea but then secretly turned around and navigated a mountainous path to pop up unexpectedly behind Perseus’ defenses.
Caught between two Roman groups, Perseus had to retreat to the coastal city of Pydna. While doing so, he wasted another chance. The two Roman forces had marched a long way to join forces, and by the time they linked up, they were exhausted while facing Perseus’ fresher army on a narrow plain. However, Perseus hesitated, allowing Paullus to establish a camp and retreat into safety. The battle would not happen that day. As both sides settled in for the night, a lunar eclipse cast an ominous shadow over the events to come.
The Battle of Pydna
Both armies likely numbered around 30,000 to 35,000 soldiers each. Perseus commanded a phalanx of roughly 21,000, supplemented by elite Macedonian light infantry, cavalry, Thracian allies, and some Greek allies and mercenaries. On the Roman side, Paullus had about 26,000 legionnaires plus additional Italian and Greek allies. The Romans also had a small group of elephants from North African allies. Anticipating an elephant attack, Perseus organized a special anti-elephant unit with spiked helmets, but it didn’t seem to make much difference in the battle.
Although both sides seemed ready for a fight, what transpired on June 22nd was somewhat spontaneous. Johstono and Taylor describe the battle at Pydna as a “meeting engagement,” where the two armies clashed unexpectedly rather than through meticulous planning. According to our sources, it all began with a lone horse or mule breaking free from the Roman side and heading toward the river both armies used for water. In trying to catch the animal, skirmishes broke out, pulling in more and more troops. By mid-afternoon—typically late to start a battle—both armies were rushing out of their camps to engage.
For the phalanx to be effective, they needed to lower their sarissas and move forward as one solid mass across a flat field. In this formation, they presented an intimidating wall of spearheads that was hard to breach. The 20-foot-long sarissa could take down the bravest soldier before they even got close to the wielder. So terrifying was the sight of a charging Macedonian phalanx that even Paullus admitted feeling fearful.
However, the phalanx struggled if it became disorganized or was attacked from the sides or rear. The Macedonian pikemen only carried light shields and short swords or daggers. If they had to turn or fight solo, the sarissa became useless, putting each soldier in a vulnerable spot. This lack of flexibility proved fatal at Cynoscephalae, where the Romans exploited weaknesses by attacking the back of the phalanx. Twenty-five years later, a similar scenario unfolded at Pydna.
While attacking a wall of spears head-on was impossible, the Romans instead pushed into the gaps that opened up within the phalanx as it advanced. According to Roman historian Livy, instead of a classic clash of battle lines, the fighting evolved into multiple smaller skirmishes as the phalanx lost cohesion under repeated Roman assaults. Without unity, the once-mighty phalanx turned into a collection of exposed individual soldiers. Matters quickly deteriorated for the Macedonians when a Roman charge led by the elephants smashed through the left flank where the battle began.
Faced with these onslaughts, the Macedonian army fell apart in just over an hour. The situation unraveled so fast that Perseus and his cavalry couldn’t even join the fray and were forced to flee. With the Romans breaking through the entire Macedonian line, the battle quickly turned into a massacre. Those attempting to escape to the coast found themselves trapped between the Roman fleet’s sailors—who attacked those trying to swim away—and the elephants lining the shore, trampling any survivors. Estimates suggest around 20,000 died, with 11,000 captured. While these numbers are likely exaggerated, they would represent almost the entirety of the Macedonian army. By the night of June 22, 168 BCE, there was virtually no Macedonian army left, while the Romans reported only about 100 casualties.
The Downfall of Macedonia
With no army left to defend itself, Macedonia fell swiftly to the Romans. Perseus attempted to flee but ended up cornered on the island of Samothrace and had no choice but to surrender. He spent his last days as a prisoner in Italy, having been paraded through the streets of Rome during Paullus’ triumphal celebration.
After waging three wars against the Macedonian kings, the Romans decided it was time to dismantle the age-old monarchy once and for all. They split the kingdom of Macedonia into four separate regions that remained free but had to pay tribute to Rome.
While the Battle of Pydna didn’t completely end the Macedonian conflicts, it solidified Rome’s control over the eastern Mediterranean. With the destruction of the last significant Macedonian army in a single afternoon, the supremacy of the Roman legion over the phalanx was undeniable.