"Ahasuerus" is given as the name of a king, the husband of Esther, in the "Book of Esther". He is said to have ruled "from India even unto Ethiopia, over an hundred and seven and twenty provinces" - that is, over the Achaemenid Empire. There is no reference to known historical events in the story; the narrative of "Esther" was invented to provide an aetiology for Purim, and the name Ahasuerus is usually understood to refer to a fictionalized Xerxes I, who ruled the Achaemenid Empire between 486 and 465 BCE. Persian kings did not marry outside a restricted number of Persian noble families and it is impossible that there was a Jewish queen Esther; in any case the historical Xerxes's queen was Amestris. In the Septuagint, the "Book of Esther" refers to this king as 'Artaxerxes' ().