能不能少用中文的网上垃圾跟我扯蛋。

quoted from Wiki:

At the Battle of Thermopylae, a small force of about 7,000 Greeks, most of which retreated, led by King Leonidas of Sparta held off a large Persian army that numbered between 200,000 and 300,000. Some historians place these figures even lower.[6] For three days, the Greeks fought a desperate action to delay the entry of the Persians into the Greek heartland where they caused a very large number of Persian casualties due to their superior discipline, weaponry, and bronze armor. The Persian forces were equipped with wicker shields and much shorter spears, but most of the Greeks were eventually forced to retreat due to an encirclement manoeuvre leaving 300 Spartans and 700 Thespian volunteers under King Leonidas in the battle to fight a desperate rearguard action. Unknown to most, were 900 Laconian Helots (serfs of the Spartan state) who also died fighting in the last stand.