The Rise of the Aztecs
The high Valley of Anáhuac—the Indian name for the Valley of Mexico, meaning “near the water”—was a compelling lure to rootless peoples seeking a more abundant life. With its equable climate and system of interconnecting lakes bordered by forests full of wild game, it was especially attractive to the nomads of the arid north. Because of its central location the Valley had been, from ancient times, a corridor through which tribes of diverse cultures passed—and sometimes remained. This cultural mélange produced a rich environment for the exchange of ideas and skills. Moreover, traders and merchants introduced exotic products from the coasts and other regions, thereby adding to the variety of life. At the same time, alien groups were frequently hostile, so that the lake country was periodically upset by violence. In the twelfth century, new city-states developed in the Valley of Mexico, interacting with each other through both peaceful and aggressive means. Throughout Mesoamerica, the links between polities multiplied in shifting relationships of exchange and political domination. In this network, central Mexico occupied the most influential position.
With the power vacuum created by the collapse of Tula in the twelfth century, primarily Nahuatl-speaking Chichimecs poured into the Valley from the north. By the early thirteenth century the Valley was teeming with activity and becoming increasingly crowded, with many of the attendant pressures so familiar to us today. It was an age of anxiety and tension. The first invader groups quickly staked out their claims, and later arrivals found little available space. The early Chichimecs settled in the proximity of established towns populated by remnants of Toltec refugees who had kept alive some semblance of the former civilization. The phenomenon so familiar in history occurred: the huntergatherers gradually adopted the more advanced ways of their sedentary neighbors.