although it is never said who wrote the book of esther, from inside evidence it is possible to make some guesses about the author and when it was written. the author was a jew, because he emphasizes where the jewish festival came from and from the jewish nationalism inside the story. the author probably lived in a persian city, because he knew persian customs well, and does not say anything about the land of judah or jerusalem. the earliest date of the book would be a little while after the events were told, for instance, about 460 b.c. (before ezra's return to jerusalem). it is also thought that the festival of purim had been celebrated some time before this book was written.