King Cyrus The Great of Persia invaded and conquered Babylon in 539 B.C.  He was called "The Great" because he was tolerant of other cultures and religions, and for his military conquests and wise rule.  He allowed conquered peoples to keep their religious and cultural practices.  Cyrus The Great freed the Jewish people in Babylon.  He encouraged the Jews to go back to their homeland.  He also encouraged them to rebuild their Jewish state.  King Cyrus became a hero to the Jewish people.

Jews were allowed to leave and return to Judah under Cyrus's Decree.  Most remained in Babylon.  However, in 538 B.C., about 42,000 Jews return to Judah.  The Jews began rebuilding the the temple in Jerusalem.  This was called the Second Temple.  Judaism began to form into the religion it is today.  The Hebrew Bible was finished.  This became the central document of the Jewish faith.