Esther, also known by her Hebrew name Hadassah, was a Jewish queen of the Achaemenid Empire during the 6th century BC. As the heroine of the biblical Book of Esther, she rose to prominence after being chosen by King Ahasuerus to replace Queen Vashti. Initially concealing her Jewish identity at the guidance of her cousin Mordecai, she eventually risked her life by approaching the monarch to expose a plot by the vizier Haman. Her courageous intervention prevented the planned genocide of the Jewish people living within the Persian kingdom.