The Book of Esther, also known in Hebrew as "the Scroll" (Megillah), is a book in the third section (Ketuvim, "Writings") of the Jewish Tanakh (the Hebrew Bible) and in the Christian Old Testament. It relates the story of a Hebrew woman in Persia, born as Hadassah but known as Esther, who becomes queen of Persia and thwarts a genocide of her people. The story forms the core of the Jewish festival of Purim, during which it is read aloud twice: once in the evening and again the following morning. Esther is the only book in the Bible that does not explicitly mention God.
The biblical Book of Esther is set in the Persian capital of Susa (Shushan) in the third year of the reign of the Persian king Ahasuerus. The name Ahasuerus is equivalent to Xerxes (both deriving from the Persian Khshayārsha), and Ahasuerus is usually identified in modern sources as Xerxes I, who ruled between 486 and 465 BC, as it is to this monarch that the events described in Esther are thought to fit the most closely.
However, classical sources such as Josephus, the Jewish commentary Esther Rabbah and the Christian theologian Bar-Hebraeus, as well as the Greek Septuagint translation of Esther, instead identify Ahasuerus as either Artaxerxes I (reigned 465 to 424 BCE) or Artaxerxes II (reigned 404 to 358 BCE).