This hypothesis that early Indo-European languages were spoken in north India with Pakistan and on the Iranian plateau at the sixth millennium BC has… - Colin Renfrew

As Renfrew put it in his archly-titled review of Mallory’s book – ‘They ride horses, don’t they?’ – the horse has assumed “an almost mythical significance in traditional Indo-European studies” (1989: 845).

[This] episode of elite dominance which brought the indo-Aryan branch of the Indo-European family to India (…) may have been as early as the floruit of the Indus civilization (…)

This area [east Macedonia], although firmly now part of Greece, has sometimes been a marginal one, and may at times have owed allegiance in different directions through a process of boundary displacement. It was indeed occupied in early classical times by Thracian tribes, barbarians who did not speak the Greek language. No doubt they did indeed speak a Thracian language akin to that in what is now Bulgaria, whose origins were suggested earlier.