Merchants
General information could be gleaned from many sources, including returning troops and travelers, but perhaps the most useful and organized conduits of general intelligence were the merchants.
The pochtecah (merchants; sing, pochtecatl)8 traded in a wide range of commodities throughout a vast geographical expanse. Not only did they travel throughout the Aztec Empire, they also went beyond it to trade with independent groups owing no allegiance to Tenochtitlan. In both areas the merchants brought back specific information for the state as well as general assessments of the local political climate, based on the way they had been received.
Much of the merchants' intelligence gathering was incidental to their primary trading functions, but they were sometimes given intelligence duties to perform for the state. King Ahuitzotl ordered merchants to penetrate the lands of Anahuac, ostensibly to trade but actually to reconnoiter. On at least some occasions when entering hostile areas beyond the Aztec Empire, the merchants disguised
themselves as natives of other areas, cutting their hair in the local manner and learning the language, because if they had been discovered, they would have been killed.
As noted, killing a merchant was a just cause of war in Meso- america, and such incidents initiated many wars. The merchants often acted as provocateurs. By demanding to trade or requesting materials for some domestic or religious purpose, they left independent cities little alternative but to expel or kill them or to become subjects of the Aztecs.
On other occasions the merchants passed through enemy lands armed with shields and swords, as if prepared for war. They met with some success when battle was thrust upon them and were rewarded by the king in the same manner as valiant warriors. If the merchants were openly attacked or were besieged, the king sent warriors to their aid. Although flight was not honored among warriors, it was rewarded among merchants because of the emphasis on obtaining their information.
The importance of the merchants’ intelligence functions increased as the empire expanded, because the time required to learn of an offense and for the army to respond increased. Consequently, rebellions and, more importantly, invasions or hostile actions by other polities could not be met in a timely manner without advance knowledge. An unanticipated attack might attain its objective before the Aztecs could muster their army and march to the defense. Though small rebellions and enemy intrusions were expected in a hegemonic system, large thrusts or massive rebellions could not be tolerated or allowed to gain momentum. Only warnings could stem such a tide, and providing them was perhaps the merchants’ most significant role in state activities. Thus the immediacy and force with which the Aztecs retaliated for the killing of their merchants had less to do with the value placed on their persons than on the need for their information. Moreover, a region where merchants were killed or excluded was a blind spot and a danger to the empire. (Ross Hassig, Aztec Warfare: Imperial Expansion and Political Control [Norman, Oklahoma: University of Oklahoma Press, 1988], 49-50)