The Abbé Brasseur de Bourbourg attempts to reconcile the general fact shown by all the earlier traditions that the primitive Nahua power was in the south, with the idea of a migration from the north apparently entertained by each of the nations of Anáhuac and by the Spanish writers. According to his idea the Nahuas, overcome by the monarchs of Xibalba, were driven from Chiapas, dwelt a few years on the Pacific coast at Tlapallantzinco, and thence migrated north-westward in different bands, following the general direction of the coast, to Sonora and Upper California. Along this route, as this author claims, distinct traces of their migration are apparent, referring perhaps, although he does not say so, to linguistic traces. In this northern region, about the Gulf of California, they established great kingdoms and built great cities, each Nahua colony becoming a centre of civilization to the wild tribes with whom it came in contact. From this region, to places in which the names Teo Culhuacan, Aztlan, etc., of the traditions may be applied, the different Nahua nations descended into Anáhuac in successive migrations from the seventh to the twelfth century, impelled by civil convulsions or the pressure of outside and warlike tribes.[III-84]
I am inclined to find in the abbé's theory a statement--too definite perhaps--of a general fact. That is, the Nahua power--established in eastern and south-eastern Mexico by the Olmec tribes almost simultaneously with its growth in the south--was after its overthrow in Central America established by exiled nobles over western and north-western Mexico. I find no evidence, however, that the Nahua power ever became settled and flourishing farther north than Durango and Sinaloa, although the influence of their institutions may, not improbably, have extended to the Sonora tribes; into California and the far north-west the Nahuas never penetrated. If a Nahua empire or political power ever really existed in the north-west, its centre was probably in the region of Quemada, in Zacatecas and Jalisco. Soon, however, the valley of Mexico became the political centre, and the subsequent history of the country was essentially a history of Anáhuac. The modern aboriginal annals of each nation dated from its rise to notice in Anáhuac, and in the traditions of previous history imperfectly communicated to the Spaniards, their former greatness in the south, their defeat and exile, their life in outside provinces, and their settlement in the valley were sadly confused.