The war between the Romans, and Philip king of Macedon, which intervened between the second and third Punic war, first afforded the former an opportunity and an excuse for interfering in the affairs of Greece. Till the time of Philip, the father of Alexander, Macedonia does not appear to have had any connexion with the rest of this celebrated portion of the ancient world; the Greeks, indeed, regarded its inhabitants as savages; but from that period, Macedonia became the most important and influential state in Greece. Its boundaries varied at different periods of its history: it seems originally to have been bounded on the east by the Egean Sea; on the south by Thessaly and Epirus; on the west by the Ionian Sea; and on the north by the river Strymon, at the mouth of which, as has been already mentioned, the Athenians founded one of their most flourishing and useful colonies. The princes of Macedonia viewed with jealousy, but for a long time were unable to prevent the states of Greece from forming colonies in the immediate vicinity of their dominions: their union, however, with the king of Persia, when he first fixed his ambition on Greece, was rewarded by a great accession of territory, which enabled them to contest the possession of the sea-coasts with the most powerful of the Greek republics. They then extended their territories to the Eastern Sea, but there were till the reign of Philip, the father of Alexander, several nations between them and the Adriatic, all of which were subdued by him; and thus this sea became their western boundary.

Some of the most celebrated cities of Macedonia were founded by foreign nations. Epidamnus, which was seated at the entrance of the Ionian Gulf, was a colony of the Corcyrians: it was the occasion of a fierce naval war between them and the Corinthians, generally called the Corinthian war. Apollonia, distant seven miles from the sea, on the river Laus, was a Corinthian colony: it was renowned for its excellent laws. On another part of the coast of the Adriatic were the sea-ports of Elyma and Bullis. The district of Paraxis, which was full of gulfs and inlets formed by the Egean Sea, had several ports, but none of any repute. From this description of Macedonia and its principal sea coasts and ports, it is evident that it possessed many advantages for commerce and naval affairs, which, however, were never embraced till the period when the Romans first turned their thoughts to Greece. Had its sovereigns been disposed to engage in commerce, the Adriatic, with its extensive and safe haven of Epidamnus, in which there were several ports, would have opened the trade to Italy; the Egean Sea, still more advantageous, would have secured the trade of Greece and Asia, by means of its spacious bays, one of which, the Sinus Thermæus, was at least sixty miles long.

The produce of Macedonia also would have favoured its commerce; the soil was every where fruitful, and, especially near the sea, abounding in corn, wine, and oil: its principal riches, however, consisted in its mines of almost all kinds of metals, but particularly of gold. In the district of Pieria, it is said, there were found large quantities of this metal in the sand, sometimes in lumps of considerable size: but by far the most productive and valuable mines of gold were in the mountain Pangæus, in a district which Philip, the father of Alexander, added to Macedonia. The people who inhabited the country near the river Strymon derived great wealth from these mines, and it was the knowledge of this, as much as the facility of obtaining timber, which induced the Athenians to found their colony near this river. The Thracians drove the Athenians from this part of Macedonia, and Philip expelled them: he paid great attention to the working of the mines; and by employing persons well skilled in this and in refining the ore, he rendered them so extremely valuable, that, according to ancient authors, he obtained the empire of Greece principally by means of the immense sums he drew from them, amounting annually, according to Diodorus, to 1000 talents of gold. When the Romans reduced Macedonia, they expressly forbade the inhabitants from working the mines of gold or silver, or refining either of those metals; permitting them, however, to manufacture any other metal.

The princes of Macedonia previous to Philip, the father of Alexander, notwithstanding the great advantage for maritime affairs and commerce afforded by the sea-coasts, bays, harbours, &c., neither practised nor understood them: this arose in a great measure from their being continually engaged in wars, or having their ports occupied or blocked up by the maritime states of Greece. Philip was the first who freed his country from these evils and inconveniences; but his thoughts were too intently and constantly fixed on other objects to allow him to turn his attention to maritime affairs or commerce. Alexander, as we have already seen, bestowed much care on his fleet, while engaged in the conquest of Asia; and when he died at Babylon, had formed the design of placing his fleets, in every port of his dominions, on a regular and extensive scale. But the advantages of Macedonia for commerce were neglected in the midst of his vast plans elsewhere, and the Macedonians, at the period of his death, were still inattentive to maritime affairs.

Philip, the antagonist of the Romans, of whose power and success he was not only jealous but apprehensive, as soon as he resolved to engage in hostilities with them, applied himself to maritime affairs. His determination seems to have been fixed when he learnt that the Romans had been defeated at the Lake of Thrasymenus: he instantly formed the plan of invading Illyrium, and then crossing over to Italy. But the latter step could not be taken, nor, indeed, could he expect to cope with the Romans, till he had formed a fleet, and trained his subjects to the management of it. At this period the Macedonians seem to have had some merchant ships; for we are informed that a petty king of Illyria seized some of them in the port of Leucas, and also all that his squadron met with on the coast of Greece, as far as Malea. This insult and attack afforded Philip an excellent reason for declaring war against Illyricum: he began by exercising the Macedonians in the art of navigation; he built ships after the Illyrian manner, and he was the first king of Macedonia that put to sea 100 small vessels at one time.

He was urged still more strongly to go on with his plan of invading Italy, when he learnt the result of the battle of Cannæ; he immediately formed an alliance with Hannibal, and engaged to invade Italy with 200 sail of ships, and plunder its eastern coasts: in return for this service he was to retain all the islands in the Adriatic, lying near the coast of Macedonia, that he might subdue.

His first naval enterprize was the siege of Oricum on the coast of Epirus, and of Apollonia on the coast of Macedonia, both of which he carried on at the same time, with 120 ships of two banks of oars. He was, however, successfully opposed by the Roman consul Laevinus, who obliged him to burn great part of his fleet, and raise the siege of Doth the places.

About twelve years afterwards, or about 200 years before Christ, Philip engaged in a maritime war with Attalus, king of Pergamus, and the Rhodians, near the isle of Chio: the fleet of Philip consisted of fifty-three decked vessels and 150 gallies; besides these he had several ships called pristis, from the figure of a large fish which was affixed to, or engraved on their bows, either to distinguish them, or as a mark of their swift sailing. The fleet of his opponents consisted of sixty-five covered ships, besides those of their allies, the people of Byzantium.

Notwithstanding, however, the exertions he made to acquire a naval force equal to that of the Romans, and the experience which his subjects gradually obtained in maritime affairs, he was not able to sustain their attacks, either by land or sea, but was compelled in a very few years to sue for peace. This he obtained, on the condition, that he should deliver up to the Romans all his covered gallies, and reserve to himself only a few smaller vessels: he was permitted, however, to retain one galley of sixteen banks of oars, a vessel rather for shew than use.

The success of the Romans, the extent of their conquests, and the ambitious views, which seemed wider and wider in proportion to their successes, alarmed Antiochus, king of Syria, who, not intimidated by the fate of Philip, resolved to declare war against them. They were never averse to engage in hostilities. The fleet of Antiochus consisted of 100 ships; that of the Romans was nearly equal in number; the ships of Antiochus, however, were inferior to those of his opponents in respect to strength and size, though surpassing them in swiftness. The hostile fleets met and engaged on the coast of Ionia; that of Antiochus was defeated, and would have been utterly captured or destroyed, had it not been for the swiftness of the vessels. In order to repair his loss, Antiochus sent for additional vessels from Sicily and Phoenicia; but these were taken on their passage by the Rhodians, who were at this time in alliance with the Romans. The Rhodians, however, in their turn were attacked and defeated by the fleet of Antiochus, near Samos, whither they had gone to join a Roman squadron.