In the meantime Xerxes, with his monstrous land army, was marching on, and the only place where it seemed to the council at the Isthmus that he could be met and stopped was at a place in Thessaly, where the mountains of Œta rose up like a steep wall, leaving no opening but towards the sea, where a narrow road wound round the foot of the cliff, and between it and the sea was a marsh that men and horses could never cross. The springs that made this bog were hot, so that it was called Thermopylæ, or the Hot Gates. The council at the Isthmus determined to send an army to stop the enemy there, if possible. There were 300 Spartans, and various troops from other cities, all under the command of one of the Spartan kings, Leonidas, who had married Gorgo, the girl whose word had kept her father faithful. They built up a stone wall in front of them, and waited for the enemy, and by-and-by the Persians came, spreading over an immense space in the rear, but in this narrow road only a few could fight at once, so that numbers were of little use. Xerxes sent to desire the Spartans to give up their arms. Leonidas only answered, “Come and take them.” The Persian messenger reported that the Greeks were sitting on the wall combing their hair, while others were playing at warlike games. Xerxes thought they were mad, but a traitor Spartan whom he had in his camp said it was always the fashion of his countrymen before any very perilous battle. Xerxes made so sure of victory over such a handful of men, that he bade his captains bring them all alive to him; but day after day his best troops fell beaten back from the wall, and hardly a Greek was slain. [Picture: Pass of Thermopylæ]