The internal dissensions of Greece produced their natural fruits; and we shall have now to relate the downfall of her independence and her subjugation by a foreign power. This power was Macedonia, an obscure state to the north of Thessaly, hitherto overlooked and despised, and considered as altogether barbarous, and without the pale of Grecian civilization. But though the Macedonians were not Greeks, their sovereigns claimed to be descended from an Hellenic race, namely, that of Temenus of Argos; and it is said that Alexander I. proved his Argive descent previously to contending at the Olympic games. Perdiccas is commonly regarded as the founder of the monarchy; of the history of which, however, little is known till the reign of Amyntas I., his fifth successor, who was contemporary with the Pisistratidae at Athens. Under Amyntas, who submitted to the satrap Megabyzus, Macedonia became subject to Persia, and remained so till after the battle of Plataea. The reigns of the succeeding sovereigns present little that is remarkable, with the exception of that of Archelaus (B.C. 413). This monarch transferred his residence from AEgae to Pella, which thus became the capital. He entertained many literary men at his court, such as Euripides, who ended his days at Pella. Archelaus was assassinated in B.C. 399, and the crown devolved upon Amyntas II., a representative of the ancient line. Amyntas left three sons, the youngest being the celebrated Philip, of whom we have now to speak.

It has been already mentioned that the youthful Philip was one of the hostages delivered to the Thebans as security for the peace effected by Pelopidas. His residence at Thebes gave him some tincture of Grecian philosophy and literature; but the most important lesson which he learned at that city was the art of war, with all the improved tactics introduced by Epaminondas. Philip succeeded to the throne at the age of 23 (B.C. 359), and displayed at the beginning of his reign his extraordinary energy and abilities. After defeating the Illyrians he established a standing army, in which discipline was preserved by the severest punishments. He introduced the far-famed Macedonian phalanx, which was 16 men deep, armed with long projecting spears.

Philip's views were first turned towards the eastern frontiers of his dominions, where his interests clashed with those of the Athenians. A few years before the Athenians had made various unavailing attempts to obtain possession of Amphipolis, once the jewel of their empire, but which they had never recovered since its capture by Brasidas in the eighth year of the Peloponnesian war. Its situation at the mouth of the Strymon rendered it also valuable to Macedonia, not only as a commercial port, but as opening a passage into Thrace. The Olynthians were likewise anxious to enrol Amphipolis as a member of their confederacy, and accordingly proposed to the Athenians to form an alliance for the purpose of defending Amphipolis against their mutual enemy. An alliance between these two powerful states would have proved an insurmountable obstacle to Philip's views: and it was therefore absolutely necessary to prevent this coalition. Here we have the first instance of Philip's skill and duplicity in negotiation. By secretly promising the Athenians that he would put Amphipolis into their hands if they would give him possession of Pydna, he induced them to reject the overtures of the Olynthians; and by ceding to the latter the town of Anthemus, he bought off their opposition. He now laid siege to Amphipolis, which, being thus left unaided, fell into his hands (B.C. 358). He then forthwith marched against Pydna, which surrendered to him; but on the ground that it was not the Athenians who had put him in possession of this town, he refused to give up Amphipolis to them.

Philip had now just reason to dread the enmity of the Athenians, and accordingly it was his policy to court the favour of the Olynthians, and to prevent them from renewing their negotiations with the Athenians. In order to separate them more effectually, he assisted the Olynthians in recovering Potidaea, which had formerly belonged to their confederacy, but was now in the hands of the Athenians. On the capture of the town he handed it over to the Olynthians. Plutarch relates that the capture of Potidaea was accompanied with three other fortunate events in the life of Philip, namely, the prize gained by his chariot at the Olympic games, a victory of his general Parmenio over the Illyrians, and the birth of his son Alexander. These events happened in B.C. 356.

Philip now crossed the Strymon, on the left bank of which lay Pangaeus, a range of mountains abounding in gold-mines. He conquered the district, and founded there a new town called Philippi, on the site of the ancient Thracian town of Crenides. By improved methods of working the mines he made them yield an annual revenue of 1000 talents, nearly 250,000l.

Meanwhile Athens was engaged in a war with her allies, which has been called the SOCIAL WAR; and which was, perhaps, the reason why she was obliged to look quietly on whilst Philip was thus aggrandizing himself at her expense. This war broke out in B.C. 357. The chief causes of it seem to have been the contributions levied upon the allies by the Athenian generals. The war lasted three years; and as Artaxerxes, the Persian king, threatened to support the allies with a fleet of 300 ships, the Athenians were obliged to consent to a disadvantageous peace, which secured the independence of the more important allies (B.C. 355).