 Modern commentators associate him with Xerxes I who reigned from 486 BC until 465 BC.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.

Ahasuerus is given as the name of the father of Darius the Mede in the "Book of Daniel".Josephus names Astyages as the father of Darius the Mede, and the description of the latter as uncle and father-in-law of Cyrus by mediaeval Jewish commentators matches that of Cyaxares II, who is said to be the son of Astyages by Xenophon.