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 Cannae; 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.