We have seen that shortly after 2200 /B.C./ nomad horsemen arrived on the Iranian plateau and that their appearance attracted the attention of Hammurabi and his counsellors. That these nomads, who were known as Kassites, were Wiros is certain, for philologists seem agreed that their language was of this type.[486] They were the first to introduce the horse into this area, and that this animal was held in reverence among them seems clear from the adoption of this beast as a divine symbol.[487] It seems unlikely that the Kassites were the sole representatives of this eastward move. It may be that it is to this date that we are to attribute the kurgans found in the Obi basin, or perhaps they found adequate pasture for their herds on the lower slopes of the Hindu Kush and the region around Balkh. We are as yet uncertain whether the group of Wiros, who may more properly claim the name of Aryas, and who spoke Indo-Iranian dialects, left the steppe at this time or on the earlier occasion but deductions drawn from linguistic evidence, from Vedic and Avestan sources, and from later Persian legend would lead us to expect that about 2000 /B.C./ the undivided Aryas were occupying the eastern parts of Russian Turkestan. A little later, perhaps, a group of these, speaking a language which had Iranian affinities, made themselves lords of eastern Armenia. These are generally known as the Mitanni or Mitani barons; Professor Sayce has suggested to me that the name Mitan is the same as Midas, which would hint at a Phrygian origin, but the Iranian affinities of their language and the early date at which they appear in the Armenian mountains suggest that they arrived before the Phrygian invasion of Asia Minor, while the fact that they were located on the eastern rather than the western side of the Armenian _massif_ leads one to believe that their line of approach was from Turkestan or the Iranian plateau on the east, rather than from Thracian territory on the west.