ch. 205
7.205.1
Since he had two older brothers, Cleomenes and Dorieus, he had renounced all thought of the kingship. Cleomenes, however, died without male offspring, and Dorieus, who had met his end in Sicily, was also no longer alive. The succession therefore fell to Leonidas since he was older than Anaxandrides' youngest son Cleombrotus and had married Cleomenes' daughter.
7.205.2
He now came to Thermopylae with the appointed three hundred he had selected, note all of whom had sons. He also brought those Thebans whom I counted among the number and whose general was Leontiades son of Eurymachus.
7.205.3
Leonidas took pains to bring only the Thebans among the Hellenes, because they were accused of medizing; he summoned them to the war wishing to know whether they would send their men with him or openly refuse the Hellenic alliance. They sent the men but intended something quite different
