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
Arcadian League join its Peloponnesian League and fight in its wars. This dominance naturally aroused anger amongst these neighboring states, and Sparta's allies proved themselves willing to rise up against their overlord on several occasions. In 418 BC, Mantinea joined a league of Peloponnesian democratic states that briefly pursued an anti-Spartan policy before being defeated at the Battle of Mantinea (418 BC). After the end of the Peloponnesian War in 404 BC, Sparta, under king Agesilaus, took several opportunities over the ensuing years to discipline a number of restive allies. In 385 BC, the Spartans attacked Mantinea and forced the city to