The Battle of Chaeroneia, 4 August 338 Bc, marks one of the decisive moments of Greek history. By now, twenty years into his reign, Philip II of Macedon had strengthened his resources, perfected his army, and achieved a dominant position in northern Greece including control of non-Greek peoples. Athens, faced with the strangulation of her supply of grain from the Black Sea, had finally declared war, and Thebes agreed to stand by her. Philip drove down into Greece, met the assembled hoplite armies on the plain of Chaeroneia, and destroyed them. The Athenians alone lost 1,000 dead and 2,000 prisoners. The cities, with the exception of Sparta, who refused to join, were now bullied by Philip into forming an alliance, the League of Corinth, of which he was voted the leading member. Their governments were packed with pro-Macedonian dependants and forbidden to engage in any independent activity. Philip was supreme in Greece, and, although the cities themselves would not have been aware of it, the era of the independent city-state was over.
Philip’s dominance had, in fact, been prophesied by the great Athenian speech-writer Isocrates. In a recitation written for the Olympic Games of 380 Isocrates had argued that the only way to bring unity to the fragmented Greek world was to launch a national crusade under one leader against Persia. In the last days of his life, he saw the triumph of Philip and congratulated him on his victory at Chaeroneia. Philip had, indeed, created a new political system, a model of monarchy whose power was based ultimately on the excellence of the monarch himself and the troops and nobles who gave personal allegiance to him. It was a model that had become totally alien to the Greek world, but now it was to prove the most successful and resilient form of government in this world for the next 200 years and even provided an exemplar for the Roman emperors.
In the first instance, the relationship between the king and his troops and war leaders depended on continual victory in war with all the benefits of booty and prestige that came with it. Philip, although in his mid-forties, was determined to maintain the momentum of success. He now embarked on the most ambitious of his plans, an invasion of Persia. The time seemed ripe. There was a power struggle for the Persian throne, and both Egypt and Babylon were in rebellion. Philip harked back 150 years, disingenuously claiming the right to lead the Greeks in revenge for Xerxes’ invasion and the desecration of the Greek shrines. By 336 an advance force of 10,000 Macedonians had already crossed the Hellespont and was campaigning along the Asian coast.