Expansion of Macedonia under Philip II a significant problem, blocking the main route into Greece. However, a second route into central Greece was available. In 480 BC, during the Battle of Thermopylae, the Persian king Xerxes had sent his army via a mountain track (the "Anopea") to outflank the pass. From this track, on the western side of Mount Kallidromon, another road led off and descended in Phocis. In 480 BC, a thousand Phocian troops were stationed above Thermopylae to guard the road and prevent a Persian assault on Phocis (though they notably failed to prevent the Persians using "Anopea"). However, in 339 BC, the Greeks
Themistocles able to travel to a meeting of the Allies, at which he proposed his strategy; with the Athenian fleet fully committed to the defence of Greece, the other Allies accepted his proposals. Thus, in August 480 BC, when the Persian army was approaching Thessaly, the Allied fleet sailed to Artemisium, and the Allied army marched to Thermopylae. Themistocles himself took command of the Athenian contingent of the fleet, and went to Artemisium. When the Persian fleet finally arrived at Artemisium after a significant delay, Eurybiades, who both Herodotus and Plutarch suggest was not the most inspiring commander, wished to sail