Book excerpt: In exploring the pattern and methods of Aztec expansion, Ross Hassig focuses on political and economic factors. Because they lacked numerical superiority, faced logistical problems presented by the terrain, and competed with agriculture for manpower, the Aztecs relied as much on threats and the image of power as on military might to subdue enemies and hold them in their orbit. Hassig describes the role of war in the everyday life of the capital, Tenochtitlan: the place of the military in Aztec society; the education and training of young warriors; the organization of the army; the use of weapons and armor; and the nature of combat.