Who was Leonidas?

The 300
   Leonidas I, king of Sparta (died 480 B.C.), was a son of King Anaxandrides, and ascended the throne about 489 B.C. When Xerxes invaded Greece, the Greek Congress assigned to Leonidas the defence of the pass of Thermopylae. His force, according to Herodotus, amounted to over 6,000 men, of whom 300 were Spartans. After the Persians had made several vain attempts to force the pass, a Greek named Ephialtes betrayed to them a mountain path, by which Hydarnes led a body of Persians to attack Leonidas in the rear. Before this manoeuvre could be completed, Leonidas, dismissing most of his allies, undertook to hold the pass with a forlorn hope of 300 Spartans, 700 Thespians and 400 Thebans. Here they resisted the main body of Xerxes' army, being attacked both in front and rear. No quarter was given or taken and it was not until the entire Spartan and Thespian corps were wiped out, that the remaining small body of Thebans surrendered. Leonidas fell early in the action, and a desperate struggle afterward took place over his body which was rescued by the Greeks, but after the surrender Xerxes ordered the head cut off and the remains crucified. The details of the gallant resistance are lost in a maze of myths, but numerous writers have paid their tribute to Leonidas and the brave band betrayed at Thermopylae.

Leonidas statue