a
species of law regulating the ordinary dealings between man and man,
that springs up in all communities, whether savage or civilized, from
custom, and from the action of judicial tribunals, which the most
despotic and absolute sovereigns feel themselves bound, so far as
relates to the private affairs of their subjects, to respect and
uphold; but, in regard to their own personal and governmental acts and
measures, they very seldom know any other authority than the impulses
of their own sovereign will.

Darius had several sons, among whom there were two who claimed the
right to succeed their father on the throne. One was the oldest son of
a wife whom Darius had married before he became king. His name was
Artobazanes. The other was the son of Atossa, the daughter of Cyrus,
whom Darius had married _after_ his accession to the throne. His name
was Xerxes. Artobazanes claimed that he was entitled to be his
father's heir, since he was his oldest son. Xerxes, on the other hand,
maintained that, at the period of the birth of Artobazanes, Darius was
not a king. He was then in a private station, and sons could properly
inherit only what their fathers possessed at the time when they were
born. He himself, on the other hand, was the oldest son which his
father had had, _being a king_, and he was, consequently, the true
inheritor of the kingdom. Besides, being the son of Atossa, he was the
grandson of Cyrus, and the hereditary rights, therefore, of that great
founder of the empire had descended to him.

Darius decided the question in favor of Xerxes, and then made
arrangements for commencing his march, with a mind full of the elation
and pride which were awakened by the grandeur of his position and the
magnificence of his schemes. These schemes, however, he did not live
to execute. He suddenly fell sick and died, just as he was ready to
set out upon his expedition, and Xerxes, his son, reigned in his
stead.

Xerxes immediately took command of the vast preparations which his
father had made, and went on with the prosecution of the enterprise.
The expedition which followed deserves, probably, in respect to the
numbers engaged in it, the distance which it traversed, the
immenseness of the expenses involved, and the magnitude of its
results, to be considered the greatest military undertaking which
human ambition and power have ever attempted to effect. The narrative,
however, both of its splendid adventures and of its ultimate fate