These, so far as yet known, commence with the third of the Seleucidæ,
and run on for many centuries, the inscriptions showing that the Greek
characters were used in the provinces of Cabul and the Punjab even so
late as the fourth century A.D. The consideration of these coins of the
Græco-Persian empire of the Seleucidæ naturally leads us to the
consideration of the Persians.

I have already shown that the Greeks and Persians held intimate
relations with each other as early as the fourth century B.C., and from
the speech of Demosthenes against a proposed war with Persia, delivered
in 354 B.C, we may well believe that they had already had a long and
intimate connection with each other. The passage rends thus:-

“All Greeks know that, so long as they regarded Persia as their common
enemy, they were at peace with each other, and enjoyed much prosperity,
but since they have looked upon the King (of Persia) as a friend, and
quarrelled about disputes with each other, they have suffered worse
calamities than any one could possibly imprecate upon them.”

The Persian empire was founded by Cyrus, about B.C. 560, and rapidly
rose to be perhaps the greatest power of the world of that age. The rise
of the Persian empire is not unlike that of the Arabian power in regard
to the wide range of conquest achieved in a very limited period. Its
actual existence, from the foundation of the empire by Cyrus in B.C. 560
to the death of Darius III., was barely two centuries and a half.

Previous to the Persian empire there existed three principal powers in
Asia--the Medes, the Chaldæans or Babylonish, and the Lydian. Of these
the Medes and Chaldæans were the most ancient, and their joint power
would seem to have extended eastward as far as the Oxus and Indus.