Battle of Thermopylae aware that his force was being outflanked, dismissed the bulk of the Greek army and remained to guard their retreat with 300 Spartans and 700 Thespians, fighting to the death. Others also reportedly remained, including up to 900 helots and 400 Thebans; these Thebans mostly reportedly surrendered. Themistocles was in command of the Greek Navy at Artemisium when he received news that the Persians had taken the pass at Thermopylae. Since the Greek strategy required both Thermopylae and Artemisium to be held, given their losses, it was decided to withdraw to Salamis. The Persians overran Boeotia and then captured the
Greece in the 5th century BC in Attica, attempting to take Athens, but were defeated at the Battle of Marathon by a Greek army of 9000 Athenian hoplites and 1000 Plateans led by the Athenian general Miltiades. The Persian fleet continued to Athens but, seeing it garrisoned, decided not to attempt an assault. During the subsequent period of peace, in 483 BC, a silver-bearing seam had been discovered in the Laurion (a small mountain range close to Athens), and the hundreds of talents mined there had paid for the construction of 200 warships to fight Aegina's piracy. In 480 BC, Darius' successor Xerxes I sent a