Judah was one of the provinces ruled over by the Persian Empire. These exiles were taken off into captivity in three waves: 605 BC (Daniel 1:1–2), 597 BC (2 Kings 24:8–17), and finally 587 BC (2 Kings 25:1–26). Now they were returning from Babylon to Jerusalem.
1 Now these were the people of the province who came up out of the captivity of those exiles whom Nebuchadnezzar the king of Babylon had carried captive to Babylonia. They returned to Jerusalem and Judah, each to his own town.