After punishing his father's murderers, he marched on Corinth, and in a general assembly of the Greeks he caused himself to be appointed to the command of the forces against Persia. On his return to Macedon, he found the Illyrians and Triballi up in arms, whereupon he forced his way through Thrace, and was everywhere victorious. But now the Thebans had been induced, by a report of his death, to take up arms, and the Athenians, stimulated by the eloquence of Demosthenes, were preparing to join them. To prevent this coalition, Alexander rapidly marched against Thebes, which, refusing to surrender, was conquered and razed to the ground. Six thousand of the inhabitants were slain, and 30,000 sold into slavery; the house and descendants of the poet Pindar alone being spared. This severity struck terror into all Greece. The Athenians were treated with more leniency. Alexander, having appointed Antipater his deputy in Europe, now prepared to prosecute the war with Persia. He crossed the Hellespont in the spring of 334 B.C. with 30,000 foot and 5,000 horse, attacked the Persian satraps at the River Granicus, and gained a complete victory, overthrowing the son-in-law of their king Darius with his own lance. As a result of the battle, most of the cities of Asia Minor at once opened their gates to the conqueror. Alexander restored democracy in all the Greek cities; and as he passed through Gordium, cut the Gordian-knot, which none should loose but the ruler of Asia. During a dangerous illness at Tarsus, brought on by bathing in the Cydnus, he received a letter insinuating that Philip, his physician, had been bribed by Darius to poison him. Alexander handed the letter to Philip, and at the same time swallowed the draught which the latter had prepared. As soon as he recovered, he advanced toward the defiles of Cilicia, in which Darius had stationed himself with an army of 600,000 men. He arrived in November, 333 B.C., in the neighborhood of Issus, where, on the narrow plain between the mountains and the sea, the unwieldy masses of the Persians were thrown into confusion by the charge of the Macedonians, and fled in terror. On the left wing, 30,000 Greek mercenaries held out longer, but they, too, were at length compelled to yield. All the treasures as well as the family of Darius fell into the hands of the conqueror, who treated them with the greatest magnanimity. Overtures for peace, made by Darius on the basis of surrendering to Alexander all Asia west of the Euphrates, were rejected.