“Yes, if I had thy youth; but many victories teach me the mistakes of the vanquished, and forbid me to join battle, immediately after a march, with a phalanx which is already drawn up and completely formed,” was Aemilius’s response to his war council after declining to go to battle the day before, according to Plutarch.
The day before, Aemilius’s army arrives at the plain to find that Persues and the Macedonian army are ready for battle in phalanx with superior numbers. Aemilius makes the call to rest his troops and make camp. His decision is questioned by his war council and he explains his decision to them in the opening quote. According to Livy, his council then responds by asking what he would have done if the Macedonians had fled. Aemilius responds, “What could we wish for better than, instead of being obliged to attack their camp in its strong position on the bank of a river, fenced with a rampart and numerous towers, we attack them in the rear after they have left their entrenchments and are making their way in a straggling column through open country.”
By the time Aemilius had left the war council, it was already mid-day and the decision was made to wait until the following day to attack. Down along the river that both the Romans and the Macedonians were using, a goat got loose from the Roman side and began to swim to the other side of the river. Three Macedonian men walk out into the river about knee deep and grab the goat. While they are walking back, the Romans that had followed the goat across the river killed on of the Macedonians while 800 of his comrades watch. Enraged, the Macedonian soldiers start to charge across the river and the battle starts.
When Aemilius sees whats going on, the Macedonians are already forming the phalanx and had begun to throw their spears. To rally his troops and get them in formation, Aemilius begins to make a charge towards the enemy. Persues sends his elephant force and allied troops along the Roman right, but the elephants are ineffective and a counter made by the Latin allies bows away the enemies left wing. The center of the phalanx is broken up by a legionnaire force. As the battle continues, Aemilius sends troops against different parts of the phalanx in order to break up the Macedonian army and flank them. The Macedonian cavalry was stationed behind the infantry, and are able to make a relatively clean escape, including the king. But the Macedonian infantry were chased down and massacred.
Livy states that never before has this many Macedonians been killed by Romans. 20,000 Macedonians dead, 6,000 that fled to Pydna were captured and killed, and 5,000 were made prisoners. There were many Roman wounded but only 100 were killed in battle.
Kennedy Hickman adds that even though the third Macedonian War was not over, Macedonian power had been broken. Perseus hands himself over to Paullus who sends him to Rome as a prisoner. At the end of the war, Macedon became a state of Rome and lost their independence. Once again the Roman legions prove their superiority over the Hellenistic phalanx style of warfare.
[Plut. Aem. 15-23]