Darius in Fausset's Bible Dictionary
A common name of several Medo-Persian kings, from a Persian
root darvesh, "restraint;" Sanskrit, dhari, "firmly
holding."
1. Darius the Mede. (See DANIEL; BABYLON;
BELSHAZZAR; CYRUS.) Daniel 5:31; Daniel 6:1; Daniel 9:1;
Daniel 11:1. This Darius "received the kingdom" (Daniel
5:31) of Babylon as viceroy from Cyrus, according to G.
Rawlinson, which may be favored by Daniel 9:1; "Darius, the
son of Ahasuerus, of the seed of the Medes, which was made
king over the realm of the Chaldaeans." He in this view gave
up the kingdom to his superior Cyrus, after holding it from
538 to 536 B.C. Abydenus makes Nebuchadnezzar prophesy that
a Persian and a Mede," the pride of the Assyrians," should
take Babylon, i.e. a prince who had ruled over the Medes and
Assyrians.
Cyrus, having taken such a prince 20 years before
Babylon's capture, advanced him to be deputy king of
Babylon. Hence he retained the royal title and is called
"king" by Daniel. Thus Astyages (the last king of the Medes,
and having no issue, according to Herodotus, 1:73, 109,127)
will be this Darius, and Ahasuerus (Achashverosh) = Cyaxares
(Huwakshatra), father of Astyages. Aeschylus (Persae, 766,
767) represents Cyaxares as the first founder of the empire
and a Mede, and Sir H. Rawlinson proves the same in
opposition to Herodotus. Aeschylus describes Cyaxares' son
as having "a mind guided by wisdom"; this is applicable both
to Darius in Daniel 6:1-3, and to Astyages in Herodotus. The
chronology however requires one junior to Astyages to
correspond to Darius the Mede and Cyrus' viceroy, whether a
son or one next in succession after Astyages, probably
Cyaxares...
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