Another group of captives leaves Babylon for Judah, and Ezra is among them. His genealogy is given to show he is from a priestly family. Ezra is given authority to re-establish the worship of God, and no one within the Persian Empire is permitted to oppose him.
It is interesting that a king who probably believes in many gods, and isn’t a real follower of God, is used to protect God’s people. We face the same thing today. We may receive protection and benefits from non-Christian governments and employers. We should be thankful that God can use those who do not choose to follow him.