THE Aztecs were not gracious victors. Their prisoners of war were frequently used for human sacrifice, as part of spectacles in which their hearts would be ripped from their bodies by priests, to be offered, still beating, to the gods. Their heads fared no better, usually ending up in a kind of skull wall, called a tzompantli in Nahuatl, the Aztec language. In its typical form it consisted of a platform, with posts connected by crossbeams onto which skulls would be threaded. Tzompantlis were generally placed in front of temples, so that friend and foe alike would be awed by the state’s power.