However this may be, the first Nahua immigrants would appear to have entered the Valley of Mexico at some time during the eighth century of our era. But the Aztecâ, part of a later swarm of Nahua, do not seem to have descended upon it until the middle of the thirteenth century, or to have founded the settlement of Mexico-Tenochtitlan until about the year 1376. At the period of their arrival in the valley they were a barbarous tribe of nomadic hunters, wandering from place to place in search of fresh hunting-grounds, precisely as did many North American Indian tribes before reservations were provided for them. Gradually, by virtue of their superior prowess in war, they achieved the hegemony of the Plateau of Anahuac, which boasted a tradition and civilization at least five hundred years old. These they proceeded to assimilate with marvellous rapidity, as is not infrequently the case when a race of hunters mingles with a settled agricultural population. Indeed, in the course of the century and a quarter which intervened between the founding of Mexico and the period of the Spanish Conquest, they had arrived at such a standard of civilization as surprised their Castilian conquerors. When the Aztecâ, abandoning their wandering life, finally settled in the Valley of Anahuac, upon the site of Tenochtitlan, now the city of Mexico, they embarked upon a series of conflicts with their neighbours, which ended in the complete subjection of these peoples. The races over whom they exercised a kind of feudal sway were many and diverse, and only the more important of these can be mentioned here. To the north dwelt the hunting Chichimecs, a related people, and the Otomi, a semi-barbarous folk, probably of aboriginal origin, and speaking a distinct language. To the west dwelt the Tarascans, whose racial affinities are unknown, or, at least, dubious. South of the Rio de las Balsas were situated the Mixtecs and Zapotecs, whose language somewhat resembled that of the Otomi and who possessed a larger measure of civilization. On the East Coast were found the Huaxtecs and Totonacs, races of Maya origin, and south-east of these lay the Olmecs, Xicalancas, and Nonoualcas, of older precedence in the land. Beyond the Isthmus of Tehuantepec were found the Maya, a people of relatively high civilization, whose origin is obscure, and into the question of whose relationship I do not propose to enter in this place. THE ANTIQUITY OF MEXICAN RELIGION