Greece in the 5th century BC BC, the Greeks, under the Spartan Pausanias, defeated the Persian army at Plataea. The Athenian fleet then turned to chasing the Persians out of the Aegean Sea, defeating their fleet decisively in the Battle of Cape Mycale, and in 478 BC the Athenian fleet captured Byzantium. In the course of doing so Athens enrolled all the island states and some mainland allies into an alliance, called the Delian League because the League's treasury was kept on the sacred island of Delos. The Spartans, although they had taken part in the war, withdrew from any further involvement, allowing Athens to become
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