In 480 he was sent with about 7000 men to hold the pass of Thermopylae against the army of Xerxes (see Battle of Thermopylae). The smallness of the force was, according to a current story, due to the fact that he was deliberately going to his doom, an oracle having foretold that Sparta could be saved only by the death of one of its kings: in reality it seems rather that the ephors supported the scheme half-heartedly, their policy being to concentrate the Greek forces at the Isthmus. Leonidas repulsed the frontal attacks of the Persians, but when the Malian Ephialtes led the Persian general Hydarnes by a mountain track to the rear of the Greeks he divided his army, himself remaining in the pass with 300 Spartans, 700 Thespians and 400 Thebans.
Perhaps he hoped to surround Hydarnes' force: if so, the movement failed, and the little Greek army, attacked from both sides, was cut down to a man save the Thebans, who are said to have surrendered.
Leonidas fell in the thickest of the fight; his head was afterwards cut off by Xerxes' order and his body crucified. Our knowledge of the circumstances are too slight to enable us to judge Leonidas' strategy, but his heroism and devotion secured him an almost unique place in the imagination not only of his own but also of succeeding times.
Go, tell the Spartans, stranger passing by,
That loyal to their law and custom, here we lie.
This entry was originally from the 1911 Encyclopedia Britannica.