[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 … - Colin Renfrew

The significance of the horse for the understanding of the distribution of early Indo-European has been much exaggerated.

[Supporters of Renfrew’s theory] “have tried to render the Indo-Iranian problem moot. They argue that the Indo-Iranian branch was somehow divided from the main body of Proto-Indo-European before the colonists brought agriculture to the Balkans. Greek and Indic are thus separated by millenniums of linguistic change - despite the close grammatical correspondences between them (... these correspondences probably represent shared innovations from the last stage of PIE).”

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).