The central Mexican peoples were fairly homogeneous in language and culture. For the indigenous peoples of central Mexico, the Conquest marked the breakup of the superstructure of the Aztec empire, but many of the component polities became bastions of indigenous social, economic, and political life under Spanish Colonial rule. Like the Spanish colonial political organization, which was built on existing native patterns, the structure of the Spanish religious structure also was. In the colonial period class divisions and family structure changed. Central Mexican native society at the time of the Conquest was divided between elites and commoners, with gradations of status within these two categories. Early sources in Spanish describing prehispanic land tenure delineate a number of different categories of land. Some major shifts occurred in the colonial period in economic relations, particularly in economic exchanges. The importance of shifts within the Nahuatl language in the colonial period has been postulated as indicators of shifts in native culture.