previous to his own elevation to the throne, founded his claim upon
the acknowledged rights of primogeniture; but Xerxes, the eldest of a
second family by Atossa, daughter of the great Cyrus, advanced, on the
other hand, a direct descent from the blood of the founder of the
Persian empire. Atossa, who appears to have inherited something of
her father's genius, and who, at all events, exercised unbounded
influence over Darius, gave to the claim of her son a stronger support
than that which he could derive from argument or custom. The intrigue
probably extended from the palace throughout the pure Persian race,
who could not but have looked with veneration upon a descendant of
Cyrus, nor could there have seemed a more popular method of
strengthening whatever was defective in the title of Darius to the
crown, than the transmission of his sceptre to a son, in whose person
were united the rights of the new dynasty and the sanctity of the old.
These reasonings prevailed with Darius, whose duty it was to nominate
his own successor, and Xerxes was declared his heir. While the
contest was yet undecided, there arrived at the Persian court
Demaratus, the deposed and self-exiled king of Sparta. He attached
himself to the cause and person of Xerxes, and is even said to have
furnished the young prince with new arguments, founded on the usages
of Sparta--an assertion not to be wholly disregarded, since Demaratus
appeared before the court in the character of a monarch, if in the
destitution of an exile, and his suggestions fell upon the ear of an
arbiter willing to seize every excuse to justify the resolution to
which he had already arrived.

This dispute terminated, Darius in person prepared to march against
the Egyptian rebels, when his death (B. C. 485) consigned to the
inexperienced hands of his heir the command of his armies and the
execution of his designs.