Macedon and responsibility for the war with Persia passed instead to his son Alexander. Background In the decade following his accession in 359 BC, the Macedonian king, Philip II, had rapidly strengthened and expanded his kingdom into Thrace and Chalkidiki on the northern coast of the Aegean Sea. He was aided in this process by the distraction of Athens and Thebes, the two most powerful city-states in Greece at that point, by events elsewhere. In particular, these events included the Social War between Athens and her erstwhile allies (357–355 BC), and the Third Sacred War which erupted in central Greece in 356 BC between the Phocians and the other members of the Delphic Amphictyonic League. Much of Philip's expansion during this period was at the nominal expense of the Athenians, who considered the north Aegean coast as their sphere of influence, and Philip was at war with Athens from 356–346 BC. Philip was not originally a belligerent in the Sacred War, but became involved at the request of the Thessalians. Seeing an opportunity to expand his influence, Philip obliged, and in 353 or 352 BC won a decisive victory over the Phocians at the Battle of Crocus Field in Thessaly. In the aftermath, Philip was made archon of Thessaly, which gave him control of the levies and revenues of the Thessalian Confederation, thereby greatly increasing his power. However, Philip did not intervene further in the Sacred War until 346 BC. Early in 346 BC, the Thebans, who had borne the brunt of the Sacred War, together with the Thessalians, asked Philip to assume the "leadership of Greece" and join them in fighting the Phocians. Philip's power was by now so great that ultimately the Phocians did not even attempt to resist, and instead surrendered to him. Philip was thus able to end a particularly bloody war without any further fighting. Philip allowed the Amphictyonic council the formal responsibility of punishing the Phocians, but ensured that the terms were not overly harsh; nevertheless, the Phocians were expelled from the Amphictyonic League, all their cities were destroyed, and they were resettled in villages of no more than fifty houses. By 346 BC, the Athenians were war-weary, unable to match Philip's strength, and had begun to contemplate the necessity of making peace. Nevertheless, when it became apparent that Philip would march south that year, the Athenians originally planned to help the Phocians (whom