XERXES I (Persian Hašajárša; Heb. 'Ahašušrôš; Greek Σέφης). — King of the Achaemenid dynasty (see ACHEMENIDI), son of Darius I and father of Artaxerxes I. He reigned from 485 to 465 B.C., when he was killed by a conspiracy. In secular history X. is renowned for his expedition to Greece to avenge the defeat of Marathon. But with the defeats at Salamis (23 Sept. 480) and Plataea (27 Aug. 479), Persian power, which suffered a second naval defeat at Mycale, was eliminated from Greece. The war officially ended in 449 with the Peace of Callias, which Cimon had won in 470 by defeating X.’s fleet once more.
The profile drawn by Herodotus (IX, 108-10) of X.’s adulterous and incestuous exploits fits perfectly with the Book of Esther, in which the King appears amid the intrigues of his harem. However, the theory that, based on the consistent Septuagint rendering, identifies the Ahasuerus of the biblical text with Artaxerxes II Mnemon is not without foundation, as already held by Eusebius and Jerome (Chronicon, Olymp. 93: CB VII, I, p. 117).
X. is also mentioned in Ezra 4:6.