Few urban developments are as multiethnic, corporate, and, in fact, exceptional as Teotihuacan, in Central Mexico. The city itself covered a surface of 20 square kilometers, with a very strict urban grid, a fact that is only present at that site in Classic Mesoamerica. It housed people from different origins in what may be called a multiethnic pact. At the base and summit of this society, traits of a corporate organization may be identified. The apartment compounds housed corporate groups that shared a particular activity. At the summit of this society, a ruling council emerging from the four districts may have been the means to appease coups d'état, in a multiethnic society with various (perhaps conflicting) interests. Nevertheless, in the intermediate level of this society, stand the quasi-autonomous neighborhood centers managed by the dynamic intermediate elite, which display of a wide variety of sumptuary goods coming from different regions, where each neighborhood center promoted alliances. The contradiction between these two elements –corporate and competitive-- may be behind the collapse of this urban society that begun by 550 CE.