The Book of Ezra is a book of the Hebrew Bible. Originally combined with the Book of Nehemiah in a single book of Ezra–Nehemiah, the two became separated in the early centuries of the Christian era. Its subject is the Return to Zion following the close of the Babylonian captivity, and it is divided into two parts, the first telling the story of the first return of exiles in the first year of Cyrus the Great (538 BC) and the completion and dedication of the new Temple in Jerusalem in the sixth year of Darius (515 BC), the second telling of the subsequent mission of Ezra to Jerusalem and his struggle to purify the Jews from what the book calls the sin of marriage with non-Jews. Together with the Book of Nehemiah, it represents the final chapter in the historical narrative of the Hebrew Bible.