Published online by Cambridge University Press: 20 January 2017
The Codex Vergara and the Codice de Santa Maria Asuncion are the most comprehensive census-cadastral native pictorial manuscripts that have survived from Central Mexico. Research reported here establishes that the documents record the household composition and landholdings of 17 localities in an area presently corresponding to identifiable barrios in and around the village of Tepetlaoztoc, located northeast of Texcoco in the Valley of Mexico. Drawn within a generation of the Conquest, probably A.D. 1539-1543, these codices present a virtually unique quantitative record for the period and provide a firm basis for interpretation of Late Horizon archaeological remains in the zone. Decipherment has revealed the first examples from Central Mexico of the use of positional notation in numerical expression, the use of the "zero" concept, and derivation and recording of field areas as well as perimeter measurements. The archaeological and ethnohistorical importance of the codices is enhanced greatly now that their spatial context is known.