Next, Darius, under whom the temple was restored, obtained the kingdom, his name being at that time Ochus. He had three Hebrew of tried fidelity as his bodyguard, and of these had, from the proof of his prudence which he had given, attracted towards himself the admiration of the king. The choice, then, being given him of asking for anything which he had formed a desire for in his heart, groaning over the ruins of his country, he begged permission to restore the city, and obtained an order from the king to urge the lieutenants and rulers to hurry forward the building of the holy temple, and furnish the expense needful to that end.
Accordingly, the temple was completed in four years; that is, in the sixth year after Darius began to reign, and that seemed, for the time, enough to the people of the Jews. For, as it was a work of great labor to restore the city, distrusting their own resources, they did not venture at the time to begin an undertaking of so great difficulty, but were content with having rebuilt the temple. At the same time, Esdras the scribe, who was skilled in the law, about twenty years after the temple had been completed (Darius being now dead who had possessed the sovereignty for nineteen years), by the permission of Artaxerxes the second (not he who had a place between the two Xerxes, but he who had succeeded to Darius Ochus), set out from Babylon with many following him, and they carried to Jerusalem the vessels of various workmanship, as well as the gifts which the king had sent for the temple of God.
Along with them were but twelve Levites; for with difficulty that number of the tribe is related then to have been found. He, having found that the Jews united in marriage with the Gentiles, rebuked them severely on that account, and ordered them to renounce all connections of that kind, as well as to put away the children which had been the issue of such marriages; and all yielded obedience to his word. The people, then, being sanctified, performed the rites sanctioned by the ancient law. But I do not find that Esdras did anything with the view of restoring the city; because he thought, as I imagine, that a more urgent duty was to reform the people from the corrupt habits which they had contracted.
Source: Sacred History (New Advent)