Roman Senate Declares Second Macedonian War; Coalition Formed

Peace at Phoenice had been a truce, not a settlement. Philip V resumed the politics of pressure—raiding, coercing, negotiating—across the Aegean and mainland Greece. In Athens, alarm edged into desperation; in Pergamon, King Attalus I counted ships and friends; in Rhodes, merchants watched sea-lanes with narrowed eyes. The complaints reached the Tiber. Livy’s narrative puts names to the list: Rhodes, Pergamon, and Athens pressed Rome to act; the consul Publius Sulpicius Galba urged a vote [2].

The Senate’s debate read as both moral argument and strategic calculus. Supporters spoke of treaty obligations and Greek appeals; skeptics measured empty treasuries after two decades of Punic war. In the end, the decision was made: war in 200 BCE [2]. If the First Macedonian War had been about denying Philip the Adriatic, the second would be about denying him Greece.

Coalition was the instrument. Pergamon brought a fleet and a motive—check a rival who had menaced Asia Minor’s coasts. The Aetolian League offered cavalry and knowledge of central Greece, enticed by the chance to punish Macedonian garrisons from Thermon to Pharsalus. Roman legions, ferried from Brundisium to Apollonia, would supply the muscle. Rhodes, although not always in perfect concert, shared interests in maritime security [2][12].

Strategy flowed from partners and terrain. From Apollonia, Roman columns swung south and east toward Thessaly; Aetolian cavalry scouted the passes toward Larisa and Pharsalus; Pergamene ships edged into the Saronic Gulf to pressure Boeotia. The names on Livy’s page—Athens, Pergamon, Rhodes—translated into an operational map where Latin orders, Greek allies, and island fleets converged on Philip’s positions [2][12].

The color of the enterprise was coalition gray—a patchwork of shields and ensigns rather than a single scarlet line. In the camps, the sounds mixed: Latin shouted over Greek, Aetolian horse bells jingled next to Roman trumpets. Politics mixed with tactics. The Romans reassured city councils in Athens and Chalcis, promising fair terms and self-government once the phalanx retreated. They also kept their eye on hard geography: the passes of Olympus, the open fields of Thessaly, the hill line Livy would later call Cynoscephalae.

Philip V, for his part, concentrated in Thessaly and tested the cohesion of the allied effort. He knew the phalanx’s value on open ground and the coalitions’ strain in long campaigns. He also knew that a defeat here would be a statement beyond a battlefield. If he lost, it would be in front of Greeks who had watched Macedon dominate for generations.

As 200 turned to 199 and 198 BCE, the campaign tightened around Philip’s supply lines and garrisons. What had started in the Senate as a debate about Athens and Pergamon became, in Thessaly’s morning mists, a sequence of marches toward a ridge of hills Polybius would later describe as “very rough and broken” [1]. The coalition had done its work. It had brought Rome to the place where the phalanx could be taught a new lesson.

Rome crossed the Adriatic to defend friends and also to test a theory: that a flexible army, partnered with allies who knew the ground and the currents, could beat a pike-wall that had ruled Greek battlefields since Philip II. The answer would come in the hills near Larisa. And it would be loud.