This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
India falls geographically into two divisions in respect of her communication with the outside world. In spite of the mountain barriers on the north, north-west and north-east, there is a volume of evidence, though of an indirect character, of considerable communication with the rest of Asia, with the portions of China and Indo-Chinese peninsula on the east, with Tibet and the western portion of China in the middle, and Central Asia stretching westwards as far as Asia Minor itself and the Mediterranean Sea on the the west. In respect of these overland communications with the west, we have comparatively speaking few glimpses by way of evidence. The discovery of the Bogaz-Keui inscription referring to the Vedic deities, Mitra, Varuna, Indra and Nasatya, and the Aryan character of the people of Mittani have led to the possibility of the inference that one section of the Aryans moved into that region. The irruptions of the Kassites who over-ran Babylonia about three centuries previous to this, also implies the existence of a powerful community of Aryan speaking people so far out. The question wherefrom they came is involved in the general problem of the Aryan home which is still a matter for discussion. The representation of apes, Indian elephants and Baktrian camels on an obelisk of Shalmanesser III in B. C. 860 gives the first clear indication of a communication between India and Assyria. It is the expansion of the Empire under Cyrus and his successor Darius that brings the Persian Empire directly into touch with India, and opens the way for the establishment of regular communication with western Asia. Similarly, on the eastern side, there is evidence of considerable early communication with the east; much of the continen tal civilisation of the Indo-Chinese Peninsula seems derivable from northern India of the Buddhistic age, some of which may possibly be referable to times earlier. This communication of northern India with the outside world is not what concerns us directly.