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
Battle of Thermopylae he selected only Spartans with living sons. The Spartan force was reinforced "en route" to Thermopylae by contingents from various cities and numbered more than 7,000 by the time it arrived at the pass. Leonidas chose to camp at, and defend, the "middle gate", the narrowest part of the pass of Thermopylae, where the Phocians had built a defensive wall some time before. News also reached Leonidas, from the nearby city of Trachis, that there was a mountain track that could be used to outflank the pass of Thermopylae. Leonidas stationed 1,000 Phocians on the heights to prevent such a