Archeological evidence suggests that Teotihuacan was a multi-ethnic city, and while the predominant language or languages used in Teotihuacan have been lost to history, Totonac and Nahua, early forms of which were spoken by the Aztecs, seem to be highly plausible. This apparent regionally diverse population of Teotihuacan can be traced back to a natural disaster that occurred prior to its population boom. At one point in time, Teotihuacan was rivaled by another basin power, Cuicuilco. Both cities, roughly the same size and hubs for trade, were productive centers of artisans and commerce. Roughly around 100 BCE, however, the power dynamic changed when Mount Xitle, an active volcano, erupted, and heavily affected Cuicuilco and the farmland that supported it. It is believed that the later exponential growth of Teotihuacan's population was due to the subsequent migration of those displaced by the eruption. While this eruption is referenced as being the primary cause of the mass exodus, recent advancements of dating have shed light on an even earlier eruption. The eruption of Popocatepetl in the middle of the first century preceded that of Xitle, and is believed to have begun the aforementioned degradation of agricultural lands and structural damage to the city. Xitle's eruption further instigated the abandonment of Cuicuilco.
Archeological evidence suggests that Teotihuacan was a multi-ethnic city, and while the predominant language or languages used in Teotihuacan have been lost to history, Totonac and Nahua, early forms of which were spoken by the Aztecs, seem to be highly plausible. This apparent regionally diverse :population of Teotihuacan can be traced back to a natural disaster th:at occurred prior to its population boom. At one point in time, Teotihuacan was rivaled by another basin power, Cuicuilco. Both cities, roughly the same size and hubs for trade, were productive centers of artisans and commerce. Roughly around 100 BCE, however, the power dynamic changed when Mount Xitle, an active volcano, erupted, and heavily affected Cuicuilco and the farmland that supported it. It is believed that the later exponential growth of Teotihuacan's population was due to the subsequent migration of those displaced by the eruption. While this eruption is referenced as being the primary cause of the mass exodus, recent advancements of datin?g have shed light on an even earlier eruption. The eruption of Popocatepetl in the middle of the first century preceded that of Xitle, and is believed to have begun the aforementioned degradation of agricultural lands and structural. damage to the city. Xitle's eruption further instigated the abandonment of Cuicuilco.