The document provides a historical overview of the Aztec civilization from around AD 1000 to the aftermath of the Spanish conquest in the 16th-19th centuries. It describes how the Toltecs took over the heritage of Teotihuacan around AD 1000 and then dispersed. It then outlines the rise of the Aztec civilization and their formation of the Triple Alliance, the expansion of their empire under rulers like Moctezuma I and Ahuitzotl, their encounter with the Spanish led by Hernan Cortes, and the devastation of indigenous populations and societies in the aftermath of the conquest through disease, exploitation, and loss of traditional ways of life and communal lands.