of the Mexican nations beyond the limits of the empire,—nations more or less independent of Aztec sway,—a glance at ancient Mexican history seems necessary, as well to throw light on the mutual relations of the peoples of Anáhuac, as to partially explain the broad extent of the Nahua civilization and of the Aztec idiom. The old-time story, how the Toltecs in the sixth century appeared on the Mexican table-land, how they were driven out and scattered in the eleventh century, how after a brief interval the Chichimecs followed their footsteps, and how these last were succeeded by the Aztecs who were found in possession,—the last two, and probably the first, migrating in immense hordes from the far north-west,—all this is sufficiently familiar to readers of Mexican history, and is furthermore fully set forth in the fifth volume of this work. It is probable, however, that this account, accurate to a certain degree, has been by many writers too literally construed; since the once popular theory of wholesale national migrations of American peoples within historic times, and particularly of such migrations from the north-west, may now be regarded as practically unfounded. The sixth century is the most remote period to which we are carried in the annals of Anáhuac by traditions sufficiently definite to be considered in any proper sense as historic records. At this period we find the Nahua civilization and institutions established on the table-land, occupied then as at every subsequent time by many tribes more or less distinct from each other. And there this culture remained without intermixture of essentially foreign elements down to the sixteenth century; there the successive phases of its development appeared, and there the progressional spirit continued to ferment for a period of ten centuries, which fermentation constitutes the ancient Mexican history. During the course of these ten centuries we may follow now definitely now vaguely the social, religious, and political convulsions through which these aboriginals were doomed to pass.
