Book or, one of the eleven books styled Ketubim, and of the five Megilloth. It is called by the Jews Megillah Esther, and sometimes simply Megillah, as it forms by itself a distinct roll. In the Christian Church it has been also called Ahasuerus, which name it bears in some copies and printed editions of the Vulgate. In the Hebrew it is placed with the other Megilloth, after the Pentateuch, between the Books of Joshua and Ecclesiastes, and sometimes among the Hagiographa, between Ecclesiastes and Daniel. In the Vulgate, Tobit and Judith are placed between Nehemiah and Esther. Luther placed it immediately after Nehemiah to prevent the books of Nehemiah and Ezra from being dismissed. It has continued to retain this position in the Reformed versions.

The principal historical difficulty of this book has been the solution of the question—What king of Persia is meant by Ahasuerus? For there has been no Persian monarch from Astyages, who died B.C. 603, and his son Cyaxares, to Darius Ochus, who died B.C. 358, or his son who died 20 years later, who has not been maintained to be the husband of Esther. Those who have most suffrages are Darius Hystaspis, Xerxes, and Artaxerxes Longimanus; for which last monarch we have the authority of Josephus and of the Septuagint Version, wherein he is called by the name of Artaxerxes. Jahn coincides with the view of Scaliger, who supposes that Amestris, the cruel and vindictive wife of Xerxes, is no other than Esther, as both the name and the character of Amestris favour the supposition that she is the Esther of the Bible. But she is said by Herodotus to have been the daughter of Otanes, a Persian, and to have been married to Xerxes before his Grecian expedition. Bellarmine, who adopts the view of Josephus, is not affected by the circumstance that, in this case, Mordecai's age must have exceeded 165 years, as he himself had known "a hale old man of 105, who was likely to live still many years." Of the true historical character of the book the existence of the feast of Darius furnishes a sufficient attestation. Of the authorship of Esther nothing is known, nor have we any data on which to form a reasonable conjecture. Augustine ascribes the book to Ezra. Eusebius ascribes it to some later but unknown author. Clemens Alexandrinus assigns it, and the Book of Maccabees, to Mordecai. The pseudo-Philo and Rabbi Azarias maintain that it was written at the desire of Mordecai by Jehoiakim, son of Joshua, who was high priest in the 12th year of the reign of Artaxerxes. De Wette assigns it to the age of the Ptolemies and Seleucids, whose era commenced B.C. 312; while Jahn maintains that it must have been written soon after the facts which it records, and before the destruction of the Persian monarchy (B.C. 330), to whose annals it appeals.

Various attempts have been made to assign to the Book of Esther only a deuter-canonical character, partly from its being unquoted in the New Testament, and partly from its being omitted in the catalogues of Melito and other writers. The former objection, however, would hold true of many other books which are yet of undoubted authority; and the latter is met to a large extent by the consideration that the Book of Esther is included under the books of Ezra. Against this slender evidence there is a large mass of positive authority which it is needless to adduce at any length. The hostility of Luther to this part of the Old Testament on account of its Judaism and "heathenish naughtiness," is considerably palliated, if, as seems probable, he referred to the whole book with its apocryphal additions. These be removed to a separate place among the apocrypha; and though they have been placed authoritatively in the canon by the council of Trent, it is certain that they were as ignominiously treated by the fathers as by Luther.