Herodotus' account is once more dominated by the desire to give prominence to the vengeance for the crime which Amasis committed in betraying Hophra his master and thrusting from the throne the legitimate ruler of Egypt (III. 407). Amasis was spared, but the punishment fell upon the son, who thus suffered for his father's sins. The sources open to Herodotus were the narratives of the Persians, of the Egyptians, and of his own people. The Greeks of Asia Minor had taken part in the campaign of Cambyses against Egypt; Greek mercenaries assisted in the defence; and as we have seen, Greeks were settled in Egypt in considerable numbers. Herodotus himself rejects the story that Cambyses was the son of the daughter of Hophra, as the Egyptians maintained by way of consolation; as well as another story that Cambyses had invaded Egypt in order to avenge the preference which Cyrus showed to the daughter of Hophra over his mother Cassandane. On the other hand, he adopts, though with hesitation, the story of the Persians that Cambyses sought a wife from Amasis, because it agrees with his own idea that ruin was brought upon Amasis by his own treachery and the daughter of the Pharaoh whom he had deposed. Deinon in his Persian History and Lyceas of Naucratis retained both these stories together in the form that Amasis sent Nitetis to Cyrus, and that she was the mother of Cambyses who invaded Egypt to avenge Hophra. The solicitation of Cambyses, and the deception of Amasis, in Herodotus, and in a still more pointed form in Ctesias, the source of which, Herodotus tells us, was the narrative of the Persians, has obviously arisen out of Persian poems about Cambyses, which required some poetical motive for the campaign against Egypt; we saw that the modern version of the poems concerning Cyrus represented the campaign against Tomyris as due to a similar motive. Hophra died in the year 570; when Cambyses ascended the throne, his youngest daughter must have been more than forty years of age. There was no need of any motive of this kind to excite Cambyses against Egypt, as has been shown above; after the fall of Lydia and Babylonia, Egypt was the natural aim for the Persian weapons.