SERSE I (Persian Hašajāria; Hebr. Ahašavērōs; Greek Ξέρθης). - King of the Achaemenid dynasty (v.), son of Dario I and father of Artaserse I. He reigned from 485 to 465 B.C., when he was killed by a conspiracy. In secular history S. remained famous for his expedition to Greece to avenge the defeat at 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 Cimone, who in 470 had once again defeated S.’s fleet.
The portrait drawn by Eredoto (IX, 108-10) of the adulterous and incestuous exploits of S. accords perfectly with that of the book of Ester, in which the King appears amid the intrigues of his harem. Nevertheless, the theory is not without foundation which, relying on the constant designation of the Septuagint, identifies the Ahasuerus of the biblical text with Artaserse II Mnemone, as Eusebio and Girolamo had already held (Chronicon, Olymp. 93: CB VII, 1, p. 117).
S. is also mentioned in Estd. 4, 6. Angelo Penna