The history of Macedonia down to the time of Philip, the father of Alexander the Great, is involved in much obscurity. The early Macedonians appear to have been an Illyrian tribe, different in race and language from the Hellenes or Greeks; but Herodotus states that the Macedonian monarchy was founded by Greeks from Argos; and, according to Greek writers, twelve or fifteen Grecian princes reigned there before the accession of Philip, who took charge of the government about the year 360 B.C., not as monarch, but as guardian of the infant son of his elder brother. Philip had previously passed several years at Thebes as a hostage, where he eagerly availed himself of the excellent opportunities which that city afforded for the acquisition of various kinds of knowledge. He successfully cultivated the study of the Greek language; and in the society of such generals and statesmen as Epaminondas, Pelopidas, and their friends, became acquainted with the details of the military tactics of the Greeks, and learned the nature and working of their democratical institutions. Thus, with the superior mental and physical endowments which nature had given him, he became eminently fitted for the part which he afterward bore in the intricate game of Grecian politics. After Philip had successfully defended the throne of Maçedon during several years, in behalf of his nephew, his military successes enabled him to assume the kingly title, probably with the unanimous consent of both the army and the nation. He annexed several Thracian towns to his dominions, reduced the Illyrians and other nations on his northern and western borders, and was at times an ally, and at others an enemy, of Athens. At length, during the Sacred War against the Phocians, the invitation which he received from the Thessalian allies of Thebes, as already noticed, afforded him a pretext, which he had long coveted, for a more active interference in the affairs of his southern neighbors. * * * * * III. INTERFERENCE OF PHILIP OF MACEDON. Of all the Grecian states, Athens alone had succeeded in regaining some of her former power, and she now became the leader in the struggle with Macedonia. In response to the invitation extended to him, Philip entered Thessaly on his southern march, but was at first repulsed by the Phocians and their allies, and obliged to retire to his own territory. He soon returned, however, at the head of a more numerous army, defeated the enemy in a decisive engagement near the Gulf of Pag'asæ, and would have marched upon Phocis at once to terminate the war, but he found the Pass of Thermopylæ strongly guarded by the Athenians, and thought it prudent to withdraw his forces.