Darius was not by any means disposed to take his repulse at Marathon as final. On the contrary, he at once set to work on making preparations for a new expedition, which should this time be one of overwhelming force, and which he determined to lead in person. A revolt which broke out in Egypt probably delayed him for a time. Anyhow, he died in 485 before his preparations were complete. He had reigned for thirty-six years and was probably in his sixty-eighth year. Xerxes, the eldest of the sons born after his accession to the throne, succeeded him without any opposition. He is said to have been averse to the scheme of an invasion, but was persuaded by those who were interested in promoting it. However this may be, the preparations were not seriously interrupted. The Egyptian insurrection was put down, and in the autumn of 481 the army intended for the invasion of Greece was assembled at Sardis. The story of the events that followed must be sought elsewhere, for I am not attempting to give a narrative of the Persian war. It must suffice to say that by August, 490, the Persian army had occupied Thessaly. It was at the famous pass which leads from this region into Locris that the Greeks made their first stand. Thermopylæ (the Hot Gates) consisted of two narrow passes, neither of them of greater width than one wheeled carriage would require, caused by the near approach of Mount Œta to the sea, or rather to an impassable morass which here formed the coast-line. (It is well to remark that considerable changes have taken place in the character of the country, the coast-line, in particular, having receded a long way eastward.) The easternmost of the two passes was that to which the name properly belonged, for here there were actual hot springs, dedicated to Hercules, and supplying medicinal baths. Between the two passes (the distance of a mile) the mountain receded from the sea, leaving a level space of about half a mile broad. At Thermopylæ proper there was a wall built by the Locrians, but at the time of which we are speaking it had fallen into ruins. It was here that Leonidas, one of the two kings of Sparta, took up his position, late, it would seem, in July. He had with him 300 Spartans, 2,500 soldiers from other parts of the Peloponnesus, a contingent of 700 from Thespiæ, one of the Bœotian towns, which dissented strongly from the pro-Persian views of their countrymen, and 400 Thebans, who came on compulsion. Thebes did not venture to refuse the demands of Leonidas while their Persian friends were still a long way off. He was also joined by contingents of the Locrians and Phocians. Both tribes had given in or were about to give in their submission to the Persians, but probably preferred the success of the Greeks. In any case, they were not prepared to resist the Greek commander-in-chief, present as he was with a much superior force.