The Horse, the Wheel, and Language

The book is subtitled "How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World". The link is to Marginal Revolution's excerpt; interesting take on ethnic identity:

And the same critical attitude toward bounded tribal territories is applied to European history. Ancient European tribal identities -- Celt, Scythians, Cimbri, Teoton, and Pict -- are now frequently seen as convenient names for chamelon-like political alliances that had no true ethnic identity, or as brief ethnic phenomena that were unable to persist for any length of time, or even as entirely imaginary later inventions.