The city of Teotihuacan in Mexico was abandoned. However, social tensions had long been simmering between the different ethnic groups, which by 550 AD had torn the city’s social fabric apart. Things disintegrated from within, and the population dispersed into the surrounding territories, just as rapidly as the city had emerged more than five centuries earlier. It had begun its urban growth more than five centuries earlier. Entire populations had crossed the Puebla Valley and the Basin of Mexico to escape the effects of seismic activity on its southern borders, including a Plinian eruption of the Popocatepetl volcano. Some of the abandoned villages brought with them their own culture, which would characterize Teotihuacan: for example, Cuicuilco had a tradition of building pyramids (think of the incredible Step Pyramids of the Moon and the Sun in Teotihuacan), while in Tetimpa, archaeologists have unearthed houses resembling those in Teotihuacan. The city was able to somehow manage the manpower and organization to build the pyramids (all without pack animals or metal tools). All these monumental constructions required sacrifices: in the two pyramids and the temple, the human remains of hundreds of victims of ritual killings were found, including remains of newborns at the corners of the Pyramid of the Sun, and those of foreign prisoners, some of them mutilated or decapitated. The city of Teotihuacan initially took an authoritarian path, only to then, around 300 AD, drastically deviate towards an egalitarian one, without a military, religious, or administrative leadership. With the egalitarian shift, construction of the pyramids suddenly stopped, but they continued to be used until 550 AD, albeit for less lethal purposes, unknown to us, before being abandoned to the forest that would eventually engulf them. During the egalitarian period, Teotihuacanha had more than decent stone houses for every family, not just the wealthy and privileged: complete sewer systems, finely plastered walls and floors, a comfortable lifestyle with a diet of corn tortillas, eggs, turkey, rabbit meat, and a milky drink called pulque, made from the fermentation of the thorny agave plant. We can certainly rule out any kind of top-down organization, although there may have been some sort of neighborhood councils.
