VII. During the second Punic war, Philip III., king of Macedonia, had attacked the Roman settlements in Illyria, invaded several provinces of Greece, and made an alliance with Hannibal. Obliged to check these dangerous aggressions, the Senate, from 540 to 548, maintained large forces on the coasts of Epirus and Macedonia; and, united with the Ætolian league, and with Attalus, king of Pergamus, had forced Philip to conclude peace. But in 553, after the victory of Zama, when this prince again attacked the free cities of Greece and Asia allied to Rome, war was declared against him. The Senate could not forget that at this last battle a Macedonian contingent was found among the Carthaginian troops, and that still there remained in Greece a large number of Roman citizens sold for slaves after the battle of Cannæ.[562] Thus from each war was born a new war, and every success was destined to force the Republic into the pursuit of others. Now the Adriatic was to be passed, first, to curb the power of the Macedonians, and then to call to liberty those famous towns, the cradles of civilisation. The destinies of Greece could not be a matter of indifference to the Romans, who had borrowed her laws, her science, her literature, and her arts.
Sulpicius, appointed to combat Philip, landed on the coast of Epirus, and penetrated into Macedonia, where he gained a succession of victories, while one of his lieutenants, sent to Greece with the fleet, caused the siege of Athens to be raised. During two years the war languished, but the Roman fleet, combined with that of Attalus and the Rhodians, remained master of the sea (555). T. Quinctius Flamininus, raised to the consulship while still young, justified, by his intelligence and energy, the confidence of his fellow-citizens. He detached the Achaians and Bœtians from their alliance with the King of Macedonia, and, with the aid of the Ætolians, gained the battle of Cynoscephalæ in Thessaly (557), where the legion routed the celebrated phalanx of Philip II. and Alexander the Great. Philip III., compelled to make peace, was fain to accept hard conditions; the first of which was the obligation to withdraw his garrisons from the towns of Greece and Asia, and the prohibition to make war without the permission of the Senate.