The histories of Herodotus;

WHEN
BOOK VII
POLYMNIA
the news of the battle fought at Marathon
reached Darius, son of Hystaspes, who was before
much exasperated with the Athenians on account
of the attack upon Sardis, he then became much
more incensed, and was still more eager to prosecute the war
against Greece. Having therefore immediately sent messengers
to the several cities, he enjoined them to prepare an army,
imposing on each a much greater number than they had furnished
before, and ships, horses, corn, and transports. When
these orders were proclaimed round about, Asia was thrown
into agitation during the space of three years, the bravest men
being enrolled and prepared for the purpose of invading
Greece. But in the fourth year the Egyptians, who had been
subdued by Cambyses, revolted from the Persians ; whereupon
Darius only became more eager to march against both.
When Darius was preparing for his expeditions against Egypt
and Athens, a violent dissension arose between his sons concerning
the sovereignty ; for by the customs of the Persians
he was obliged to nominate his successor before he marched
out on any expedition. Now Darius, even before he became
king, had three sons born to him by his former wife, the
daughter of Gobryas; and after his accession to the throne,
four others by Atossa, daughter of Cyrus. Of the former,
Artabazanes was the eldest ; of those born afterward, Xerxes
and these two not being of the same mother, were at variance.
Artabazanes urged that he was the eldest of all the sons, and
that it was the established usage among all men that the eldest
son should succeed to the sovereignty : on the other hand,
Xerxes alleged that he was son of Atossa, daughter of Cyrus,
and that it was Cyrus who had acquired freedom for the Per-
sians. When Darius had not yet declared his opinion, at this
very conjuncture Demaratus, son of Ariston, happened to
come up to Susa, having been deprived of the kingly office at
Sparta, and having imposed on himself a voluntary exile from
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