(M710) In the year 383 B.C., Philip attacked Lyeophron, of Pheræ, in Thessaly. Onomarchus, then victorious over the Thebans, advanced against Philip, and defeated him in two battles, so that the Macedonian army withdrew from Thessaly. But Philip repaired his losses, marched again into Thessaly, defeated the Phocians, and slew Onomarchus. His conquest of Pheræ was now easy, and he rapidly made himself master of all Thessaly, and expelled Lycophron. He then marched to Thermopylæ, to the great alarm of Athens, which sent a force to resist him, which force succeeded in defending the pass, and keeping Philip, for a time, from entering Southern Greece. The Phocians also rallied, again availed themselves of the treasure of Delphi, and melted down the golden ornaments and vessels which Crœsus, the Lydian king, had given one hundred years before, among which were three hundred and sixty golden goblets, from the proceeds of which a new army of mercenaries was raised. (M711) The power of Philip was now exceedingly formidable, and his successes inspired great alarm throughout Greece, as would appear from the first Philippic of Demosthenes, delivered in B.C. 352. But the Grecian States had no general able to cope with him on the land, while he created a navy to annoy the Athenians at sea. (M712) For a time, however, the efforts of Philip were diverted from Southern and Central Greece, in order to conquer the Olynthians. They were his neighbors, and had been his allies; but the expulsion of the Athenians from the coast of Thrace and Macedonia now alarmed the Olynthians, together with the increasing power of Philip, so that they concluded a treaty of peace with Athens. Hostilities broke out in the year 350 B.C., and Demosthenes put forward all his eloquence to excite his countrymen to vigorous war. Athens, partially aroused, sent a body of mercenaries to the assistance of Olynthus, one of the most flourishing of the cities of Chalcidia, southeast of Macedonia. But before effective aid could he rendered, the island of Eubœa, through the intrigues of Philip, revolted from Athens. It was in an expedition to recover that island that Demosthenes served as a hoplite in the army, under Phocion as general. It was not till the summer of B.C. 348 that this territory was recovered by Athens. In the year following, Athens made great exertions in behalf of Olynthus, and amid great financial embarrassments. Three expeditions were sent into Chalcidia, under the command of Chares, numbering altogether four thousand Athenians and ten thousand mercenaries. But they were powerless against the conquering arms of Philip, who completely overran and devastated the peninsula, taking thirty-two cities, and selling the people for slaves. At last Olynthus fell, B.C. 347, and the spoils of this old Hellenic city were divided among the soldiers of the conqueror, who celebrated his victories by a splendid festival.