For, as he had two elder brothers, Cleomenes and Dorieus, he was far from any thought of the kingdom.  However, Cleomenes having died without male issue, and Dorieus being no longer alive—­having ended his days in Sicily—­the kingdom thus devolved upon Leonidas; both because he was older than Cleombrotus—­for he was the youngest son of Anaxandrides—­and also because he had married the daughter of Cleomenes.  He then marched to Thermopylae, having chosen the three hundred men allowed by law, and such as had children.  On his march he took with him the Thebans, whose numbers I have already reckoned, and whom Leontiades, son of Eurymachus, commanded.  For this reason Leonidas was anxious to take with him the Thebans alone of all the Greeks, because they were strongly accused of favoring the Medes:  he therefore summoned them to the war, wishing to know whether they would send their forces with him, or would openly renounce the alliance of the Grecians; but they, though otherwise minded, sent assistance.

The Spartans sent these troops first with Leonidas, in order that the rest of the allies, seeing them, might take the field, and might not go over to the Medes if they heard that they were delaying; but afterward—­for the Carnean festival was then an obstacle to them—­they purposed, when they had kept the feast, to leave a garrison in Sparta and to march immediately with their whole strength.  The rest of the confederates likewise intended to act in the same manner; for the Olympic games occurred at the same period as these events.  As they did not, therefore, suppose that the engagement at Thermopylae would so soon be decided, they despatched an advance-guard.

The Greeks at Thermopylae, when the Persians came near the pass, being alarmed, consulted about a retreat; accordingly, it seemed best to the other Peloponnesians to retire to Peloponnesus, and guard the Isthmus; but Leonidas, perceiving the Phocians and Locrians were very indignant at this proposition, determined to stay there, and to despatch messengers to the cities, desiring them to come to their assistance, they being too few to repel the army of the Medes.

While they were deliberating on these matters, Xerxes sent a scout on horseback, to see how many they were and what they were doing; for while he was still in Thessaly, he had heard that a small army had been assembled at that spot, and as to their leaders, that they were Lacedaemonians, and Leonidas, who was of the race of Hercules.  When the horseman rode up to the camp, he reconnoitred, and saw not indeed the whole camp, for it was not possible that they should be seen who were posted within the wall, which having rebuilt they were now guarding; but he had a clear view of those on the outside, whose arms were piled in front of the wall.  At this time the Lacedaemonians happened to be posted outside; and some of the men he saw performing gymnastic exercises, and others combing their hair.  On beholding this he was astonished, and ascertained their number, and having informed himself of everything accurately, he rode back at his leisure, for no one pursued him and he met with general contempt.  On his return he gave an account to Xerxes of all that he had seen.