• Pekka Hämäläinen, The Comanche Empire (New Haven: Yale University Press, 2008).


Why were mid-nineteenth-century Hispanic populations so small in what is now the American Southwest, after centuries of colonization? A brilliant new literature provides a model of explanation in the authority of formidable indigenous polities, especially that great power that Pekka Hämäläinen reveals to us in his book The Comanche Empire.1 Employing an exercise in cartographic history, centered on the Pecos River Valley, we can confirm a hypothesis drawn from that theoretical model: Comanche sway was so great that European mapmakers appear to have lost knowledge about that geographical region. This new historical model deserves close attention from scholars. In this forum, four leading historians, drawn from different fields, assess the contribution of The Comanche Empire.