So far as we can tell Cyrus was long in coming to his prime, and did not attain to his full powers till he had reached the years of manhood. Sprung from the royal house of the Persians, grandson of Achæmenes, he grew up at Pasargadae, and rendered service as a vassal to his sovereign. While performing courtly and martial duties at Ecbatana, the extinction of the male line of the house of Deioces, and the rival claims which the death of Astyages would call forth, opened to him the prospect of obtaining independence for himself and the Persians. When once more among his own people, the suspicion of Astyages forces arms into the hands of himself and his father. Astyages penetrates into the mountains of Persia, and Cambyses is slain; only after severe struggles are the Medes beaten back. Cyrus avails himself of his success in order to carry war into Media. About eighty years after Achæmenes had joined Phraortes Cyrus marches victoriously into Ecbatana. He at once aims at a higher object. The dominion of the Medes must pass over to the Persians. Babylon and Lydia give him time to subjugate the Parthians and Hyrcanians, to make war on the Sacae and Bactrians, to reduce the Cadusians, Armenians, and Cappadocians. When yet unprepared or engaged in other conflicts, he is attacked by Croesus. A brilliant campaign carries him far beyond the defensive; he overthrows the Lydian empire and advances to the shore of the Ægean. While his generals complete the reduction of Asia Minor he turns again to the East; once more Babylon gives him time to establish and extend his empire in the table-land of Iran. Secure on the East and West he proceeds to the decisive struggle with Babylon. In the first campaign he crosses the Tigris and secures the passage; in the second he defeats Nabonetus, captures Sepharvaim, storms Babylon, obtains possession of Borsippa, subjugates Syria, and the Phenician cities. After the annihilation of the Babylonian kingdom, Cyrus extends the borders of his empire still further to the East. The nations on the right bank of the Indus, the Chorasmians and the Sogdiani, are reduced, and the Jaxartes becomes the limit of the kingdom. Thus by unwearied energy, restless effort, and tough endurance, Cyrus achieved a career which has no equal; from being chief of the Persian tribes he became sovereign of Asia. As Xenophon says, his kingdom extended from regions which are rendered uninhabitable by heat, to others which are uninhabitable by reason of the cold. This aim Cyrus had pursued with great determination; he had not been guilty of any wild outbursts. A general, rapid in decision and tenacious in purpose, he had understood how to meet failure and make himself master of the most difficult undertakings. Other military princes of the East have achieved greater conquests in a shorter space of time than Cyrus, but none understood how to preserve the empire he had won, and make it permanent, as Cyrus did.