How many spartens defended in the battle of Thermopylae?

In the Battle of Thermopylae, a small force of approximately 300 Spartan warriors, led by King Leonidas, defended against a vastly larger Persian army in 480 BC. Alongside the Spartans, there were also several hundred other Greek allies, but the Spartans were the most notable and committed to the stand. Their bravery and sacrifice have become legendary symbols of courage and resistance against overwhelming odds.