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
Battle of Hysiae (417 BC) destroyed the town and fortress of Hysiae and had its male population executed. The campaign is described by the historians Thucydides (5.83.2), who actually fought in the war, and Diodorus Siculus (12.81.1), who wrote in the 1st century BC, over two hundred years later. Thucydides says that the Spartans marched against Argos in the winter of 418–417 BC with all their allies, but failed to take the city of Argos. The Spartans did, however, capture and destroy the Argive town of Hysiae, taking all the male citizens as hostages. The hostages were subsequently killed. With Hysiae destroyed, the Spartans left