The Book of Esther in the Old Testament relates the story of Esther, who was chosen by Ahasuerus, king of Persia, unaware that she was Jewish, to be his wife.

Shortly after their marriage, the king's chief minister Haman decreed that all Jews living in Persia should be slaughtered, and Esther went to the king, at the request of her cousin Mordecai, to plead with him to repeal this rule. To appear before him without having been summoned was punishable by death, even for his wife, and Esther is therefore a symbol of great courage in the face of overwhelming danger. Ahasuerus not only pardoned Esther and overturned the decree, but ordered Haman to be hanged.

The role of Esther was considered to prefigure the Virgin as intercessor.

Luca Signorelli
about 1519-22
Luca Signorelli: 'Predella: Esther, and Life of Saint Jerome'
Sebastiano Ricci
probably 1730-4
Sebastiano Ricci: 'Esther before Ahasuerus'