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. Of these nations the Babylonians were the most highly civilized, and, did time permit, we might find much that would interest and instruct in examining the various facts relating to the arts and sciences amongst these nations. We know that arts and sciences must have been diligently cultivated amongst them, and that magic and astrology were held in high repute. That the Persians were well acquainted with other nations is shown clearly from the remains of their great city of Persepolis, where the sculptured figures represent many types of mankind--the negro, with thick lips and flat nose, and with his crisp, wooly hair, clearly cut; and the half-naked Indian, with his distinguishing features, being easily singled out from many others. Persia held sway over a huge district of India--the limits of this are not known; but, in addition, they were well acquainted with a large portion of the north-western part of India. The traditions and historical records of the Persians are contained in the famous series of writings culled the Zend-avesta. These writings are, it is thought, of an age even before the Persian dynasty was established; and it has been shown by the researches of M. Anguetil and Sir W. Jones that there is indeed a great probability of the Zend having been a dialect of the ancient Sanscrit language. In the vocabulary attached to M. Anguetil’s great work on the Zend-avesta no less than 60 to 70 per cent. of the words are said to be pure Sanscrit. As the oldest known language of Persia was Chaldæic, we are again thrown back on Indian sources for the origin of the great book of the ancient Persians. Even the name of the priests of the Persian religion of Zoroaster, Mag or Magi, is of Sanscrit derivation. The Persians kept up an enormous army, which was spread through all the various provinces and Satrapies, and consisted in great part of paid auxiliaries. In at least the later period of Persian power the Greeks were preferred to all others, and in the time of Cyrus the Younger they composed the flower of the Persian army, and were employed in garrisoning most of the chief cities of Asia Minor.