Writing has a long history in Mesoamerica from the early writing system of the Formative Period Olmec culture to the Aztec manuscripts of the early Colonial period. Less than 100 Mixtec and Aztec manuscripts are known from the pre-Hispanic and early Colonial periods that indicate the role of writing both before, during, and after the conquest of New Spain. This talk explores the Mixtec and Aztec manuscripts of the late pre-Hispanic and early Colonial periods, including an analysis of naming and writing conventions, toponyms, and their function as legal documents.