Final stand of the Spartans and Thespians
Leonidas, realizing that further fighting would be futile, dismissed all Greek forces save the surviving Spartans and Thebans on August 11 the Spartans having pledged themselves to fight to the death, and the Thebans held as hostages as Thebes' loyalty to Greece was questioned. However, a contingent of about 700 Thespians, led by Demophilus, refused to leave with the other Greeks. Instead, they chose to stay in the sacrificial effort to delay the advance and allow the rest of the Greek army to escape.
The significance of the Thespians' refusal to leave should not be ignored. The Spartans, as brave as their sacrifice indubitably was, were professional soldiers, trained from birth to be ready to give their lives in combat as Spartan law dictated. Conversely, the Thespians were citizen-soldiers (Demophilus, for example, made his living as an architect) who elected to add whatever they could to the fight, rather than allow the Spartans to be annihilated alone. Though their bravery is often overlooked by history, it was most certainly not overlooked by the Spartans, who are said to have exchanged cloaks with the Thespians and promised to be allies for eternity.[citation needed]
The fighting was said to have been extremely brutal, even for hoplite combat. As their numbers diminished the Greeks retreated to a small hill in the narrowest part of the pass. The Thebans took this opportunity to surrender to the Persians[28]. After their spears broke, the Spartans and Thespians kept fighting with their xiphos (short swords), and after those broke, they were said to have fought with their bare hands, teeth and nails.
The Greeks killed many Persians, including two of Xerxes' brothers. In this final stand, Leonidas was eventually killed; rather than surrender, the Spartans fought fanatically to defend his body. To avoid losing any more men, the Persians killed the last of the Spartans with flights of arrows.