Esther, book of means in the bible: This article contains the historical background that lead to the establishment of the Jewish Feast of Purim. This story is from the period of the Captivity. Ahasuerus, king in Persia, was most likely Xerxes. He had made the decision to divorce his queen Vashti, because she wouldn’t show her beauty to people or the princes. Esther, the adopted daughter of Mordecai, the Jew was selected to succeed her. Haman, the chief of courtiers at King’s Court, was a hateful man and obtained, after casting lots, a decree that all Jews should be executed. Esther revealed her nationality at great risk and won a reversal. In honor of the deliverance, two days of feasting were to be observed annually. Purim was their name because they were named after the Puritan lot Pur, which Haman cast to destroy the Jews.
(in Bible Dictionary)