Battle of Plataea other. The Allies initially adopted a strategy of blocking land and sea approaches to southern Greece. Thus, in August 480 BC, after hearing of Xerxes' approach, a small Allied army led by Spartan King Leonidas I blocked the Pass of Thermopylae, while an Athenian-dominated navy sailed to the Straits of Artemisium. Famously, the massively outnumbered Greek army held Thermopylae for three days before being outflanked by the Persians, who used a little-known mountain path. Although much of the Greek army retreated, the rearguard, formed of the Spartan and Thespian contingents, was surrounded and annihilated. The simultaneous Battle of Artemisium, consisting
Delian League to the Persian Empire, and Eretria was duly destroyed. However, the invasion ended in 490 BC with the decisive Athenian victory at the Battle of Marathon. Between the two invasions, Darius died, and responsibility for the war passed to his son Xerxes I. Xerxes then personally led a second Persian invasion of Greece in 480 BC, taking an enormous (although oft-exaggerated) army and navy to Greece. Those Greeks who chose to resist (the 'Allies') were defeated in the twin simultaneous battles of Thermopylae on land and Artemisium at sea. All of Greece except the Peloponnesus thus having fallen into Persian