The book commences with a feast organized by Ahasuerus, initially for his court and dignitaries and afterwards for all inhabitants of Shushan. Ahasuerus orders his wife Vashti to display her beauty before the guests. She refuses, and the King's advisors warn that, if unpunished, her actions would inspire other wives to disobey their husbands. Ahasuerus removes her as queen. (Jews believe that she was executed, He then orders all young women to be presented to him, so he can choose a new queen to replace Vashti. One of these is Esther, who was orphaned at a young age and is being fostered by her uncle Mordechai."
(Summary by Wikipedia)