Darius I (Darius the Great)dərĪˈəs, d. 486 B.C., king of ancient Persia (521–486 B.C.), called also Dariavaush and Darius Hystaspis (after his father, Hystaspes or Vishtaspa). A distant cousin of Cambyses II (see under Cambyses), he succeeded to the throne after the fall of the impostor claiming to be Smerdis. The first years of his reign were spent in putting down revolts in Persia, Media, Babylonia, and the East. He then proved himself the true successor of Cyrus the Great and one of the most able of the Achaemenids by revising and increasing Cyrus' use of the satrapies. These provinces were ruled by satraps, who functioned as viceroys and were responsible only to the Great King; the satraps were, however, checked by generals, ministers of home affairs, and secret police, all of whom were responsible to Darius alone. This system proved so efficient that it was later adopted by Alexander the Great and, still later, by the Parthians. Darius also undertook lengthy campaigns; an incursion against the Scythians began in 512 B.C., and it involved taking Thrace and Macedonia and building a bridge across the Danube. He was involved in a dispute with the Greeks after giving refuge to the tyrant Hippias, but more serious quarrels began with the revolt (c.500 B.C.) of the Ionian cities against Persian rule. Having put down the rebels, Darius set out to punish the Greek city-states that had aided in the insurrection (see Persian Wars). His first expedition was turned back by storms; his second met defeat in the memorable battle of Marathon (490 B.C.). Darius consolidated Persian power in the East, including NW India. He continued Cyrus' policy of restoring the Jewish state, and under his auspices the rebuilding of the temple in Jerusalem was completed in 515 B.C. For this reason he is mentioned warmly in Ezra, Haggai, and Zechariah. He left the Behistun Inscription. Written in Old Persian, Assyrian, and Susian (the Iranian language of Elam), it provided the key for deciphering Babylonian cuneiform. Upon his death he was succeeded by his son Xerxes I.