Esther (originally Hadassah) is the eponymous heroine of the Book of Esther. In it, Ahasuerus, the king of the Achaemenid Empire, seeks a new wife after his queen, Vashti, is deposed for disobeying him. Esther is chosen to fulfill this role due to her beauty. Ahasuerus' grand vizier, Haman, is offended by Esther's cousin and guardian, Mordecai, due to his refusal to prostrate himself before Haman. Consequently, Haman plots to have all the Jewish subjects of Persia killed, and convinces Ahasuerus to permit him to do so. However, Esther foils the plan by revealing Haman's eradication plans to Ahasuerus, who then has Haman executed and grants permission to the Jews to kill their enemies instead, as royal edicts (including the order for eradication issued by Haman) cannot be revoked under Persian law.
The Book of Esther provides the traditional explanation for the Jewish holiday of Purim, celebrated on the date given in the story for when Haman's order was to go into effect, which is the day that the Jews killed their enemies after the plan was reversed. The book exists in two related forms: a shorter Hebrew-sourced version found in Jewish and Protestant Bibles, and a longer Greek-sourced version found in Catholic and Orthodox Bibles.
When she is introduced, in Esther 2:7, she is first referred to by the Hebrew name Hadassah. This name is absent from the early Greek manuscripts, although present in the targumic texts, and was probably added to the Hebrew text in the 2nd century CE at the earliest to stress the heroine's Jewishness. The name "Esther" probably derives from the name of the Babylonian goddess Ishtar or from the Persian word cognate with the English word "star" (implying an association with Ishtar) though some scholars contend it is related to the Persian words for "woman" or "myrtle".
Book of Esther
In the third year of the reign of King Ahasuerus of Persia the king banishes his queen, Vashti, and seeks a new queen. Beautiful maidens gather together at the harem in the citadel of Susa under the authority of the eunuch Hegai.