Ahasuerus said to be the same as Xerxes I
Etymology
The Hebrew form is believed to have derived from the Old Persian name of Xerxes I, Xšayāršā (< xšaya 'king' + aršan 'male' > 'king of all male; Hero among Kings'). That became Babylonian Aḥšiyaršu (𒄴𒅆𒐊𒅈𒋗, aḫ-ši-ia-ar-šu) and then Akšiwaršu (𒀝𒅆𒄿𒈠𒅈𒍪, ak-ši-i-wa6-ar-šu) and was borrowed into Hebrew as אֲחַשְׁוֵרוֹשׁ‎ Ăḥašwêrôš and thence into Latin as Ahasuerus, the form traditionally used in English Bibles.The Persian name was independently rendered in Ancient Greek as Ξέρξης Xérxēs. Many newer English translations and paraphrases of the Bible have used the name Xerxes.Biblical references
Book of Esther
"Ahasuerus" is given as the name of a king, the husband of Esther, in the Book of Esther. He is said to have “ruled over a hundred and twenty-seven provinces from India to Nubia" — that is, over the Achaemenid Empire. There is no reference to known historical events in the story; some consider the narrative of Esther was 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 unlikely 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 the king as 'Artaxerxes,' who was the younger son of Xerxes (Ancient Greek: Ἀρταξέρξης).Historical identification
Numerous scholars have proposed theories as to who Ahasuerus represents. Most scholars generally identify him with Xerxes I, as did 19th-century Bible commentaries. Three factors, among others, contribute to this identification:It is agreed the Hebrew 'Ahasuerus' descended from the Persian names for Xerxes I.
Historian Herodotus describes Xerxes I as being susceptible to women and in the habit of making extravagant offers to them, just as he did to Esther ("up to half my kingdom"). Herodotus mentions that the Persian empire stretched from India to Ethiopia and also refers to the magnificent royal palace in Shushan (Susa), corroboration of what is stated in the Book of Esther. In addition Herodotus mentions an assembly of Persian nobles called by Xerxes to advise him on the proposed war against Greece. Although Herodotus does not give the location of this assembly, the date – "after Egypt was subdued" – corresponds to Xerxes' third year when Esther records an assembly of Persian nobility at a feast. (Histories VII.8) Herodotus also mentions that following his defeat at Salamis Xerxes I became involved in harem intrigues involving his wife Amestris and his daughter-in-law, with whom he became enamoured. (Histories IX.108) Herodotus relates this occurred in the tenth month of his seventh year as king – the same time Ahasuerus was choosing beautiful women for his harem (Esther 2:16).
Annals from the reign of Xerxes I mention an otherwise unattested official by the name of "Marduka", which some have proposed refers to Mordecai, as both are mentioned serving in the king's court.The Septuagint, the Vulgate, the Midrash of Esther Rabbah, I, 3 and the Josippon identify the king as Artaxerxes I, and the historian Josephus relates that this was the name by which he was known to the Greeks. The Ethiopic text calls him Arťeksis, usually the Ethiopic equivalent of Artaxerxes.Book of Ezra
Ahasuerus is also given as the name of a King of Persia in the Book of Ezra. Modern commentators associate him with Xerxes I who reigned from 486 BCE until 465 BCE. Other identifications have been made for Cambyses II or with Bardiya (Greek Smerdis) who reigned (perhaps as an imposter) for seven months between Cambyses II and Darius I.