that made up the empire none can be positively identified by name with any of the later peoples found in Anáhuac, though there can be little doubt that several of the latter were descended directly from the Toltecs and contemporary tribes; and indeed it is believed with much reason that the semi-barbarous Otomís of Anáhuac, and several nations beyond the limits of the valley, may date their tribal history back to a period even preceding the Toltec era. During the most flourishing period of its traditional five centuries of duration, the Toltec empire was ruled by a confederacy similar in some respects to the alliance of later date between Mexico, Tezcuco, and Tlacopan. The capitals were Culhuacan, Otompan, and Tollan, the two former corresponding somewhat in territory with Mexico and Tezcuco, while the latter was just beyond the limits of the valley toward the north-west. Each of these capital cities became in turn the leading power in the confederacy. Tollan reached the highest eminence in culture, splendor, and fame, and Culhuacan was the only one of the three to survive by name the bloody convulsions by which the empire was at last overthrown, and retain anything of her former greatness.
Long-continued civil wars, arising chiefly from dissensions between rival religious factions, resulting naturally in pestilence and famine, which in the aboriginal annals are attributed to the direct interposition of irate deities, gradually undermine the imperial thrones. Cities and nations previously held in subjection or overshadowed by the splendor and power of Tollan, take advantage of her civil troubles to enlarge their respective domains and to establish independent powers. Distant tribes, more or less barbarous, but strong and warlike, come and establish themselves in desirable localities within the limits of an empire whose rulers are now powerless to repel invasion. So the kings of Tollan, Culhuacan, and Otompan lose, year by year, their prestige, and finally, in the middle of
