Steppes Horsemen (Kurgan) Culture Developed in Steppe Zone from Ishim River to Danube River
The latest data on horse domestication indicates the Steppes Horsemen (Kurgan) Horse Culture developed after somebody first domesticated and rode the horse in the Botai Culture east of the Ishim River around 3700 BC. To better understand the impact upon Europe of the western steppes horsemen, I strongly suggest you read Chapter Thirteen of The Horse, The Wheel, and Language . I own and have read this excellent book, and consider it fortunate that you can read chapter 13 on the web for free.
However, I consider it much more likely that the eastern steppes horsemen went south along the Caspian Coast (availability of fresh water) to the Zagros Mountains and on from there through Iran to the Indus Valley, South Mesopotamia, the Jazira, and Anatolia leaving their trail of Indo-European languages (click this last site’s map to see the spread of the language, and note this is far from a unanimous approval) and particularly in Anatolia, the Mitanni, a substrate in proto-Sumerian or Euphratic, and Indo-Iranian.
This is where Indo-European and Steppes Horsemen theories stand at this time. Of course, this is very important to me in writing the new novel.
Thanks for visiting,
R. E. J. Burke