Darius II, d. 404 B.C., king of ancient Persia (423?-404 B.C.); son of Artaxerxes I and a concubine, hence sometimes called Darius Nothus [Darius the bastard]. His rule was not popular or successful, and he spent most of his reign in quelling revolts in Syria, Lydia (413), and Media (410). He lost Egypt (410), but through the diplomacy of Pharnabazus, Tissaphernes, and Cyrus the Younger he secured much influence in Greece in the Peloponnesian War. Artaxerxes II succeeded Darius, but the succession was challenged by Cyrus the Younger.