Greetings folks, The Iranian and the Aryan(both subset of the greater Indo-Iranian family) civilizations of OTL have mostly a nomadic root in their founding, probably due to the way they expanded. They expanded, from what it seems most plausible, from the Corded Ware Culture in Northeast Europe into the mostly arid regions of Central Asia, where they parted ways and split into the various groups who migrated and influenced regions from Levant(Mitanni Aryans) in the West to India in the East(Dardic, Gandhara and Vedic Aryans) with the Western Iranian peoples dominating the regions in between and Eastern Iranian peoples dominating the Nomadic regions to the North(Sogdia, Scythia, Sarmatia). All these were born mostly out of Nomadic tribes(Medes(ancestors of Kurds), Old Persians, Aryans, Scythians, Sogdians being the prominent and their sub-tribes). Civilizations with a Nomadic root tend to develop in a particular way, which happened in OTL, so in this ATL, I want to experiment how they would grow if they adopted sedentary lifestyle before or just after splitting from the Corded Ware culture. Of course, parts to the East of the Caspian(where the Andronavo and Sintashta Culture had their root) aren't suitable to found large Sedentary societies so we need to find greener regions in today's Russia or Caucasus to have them found such an empire. These were people of the White European stock, for the most part and so I want to experiment how the Civilization developments of Russia, Caucasus and the adjacent parts happen and also the Genetic impact on the other regions in the later days and how different would the History unfold in the later days. After establishing themselves strongly in the Southern Russia or the Caucasus, they could enter Iran and Gandhara regions like how they did in OTL and settle the River valleys there and expand into Medea, in the same way.