Archaeological remains of Postclassic civilization
The early Postclassic period (900–1200) in central Mexico is associated with three major sites, all of which began in Classic times: Cholula in Puebla, Xochicalco in Morelos, and Tula in Hidalgo. Cholula was a major centre as far back as Early Classic times, probably as a political dependency of Teotihuacán. It reached its maximum growth in Late Classic times, following the collapse of Teotihuacán, when the largest structure ever built by Meso-Americans was erected (see above Cholula).
In Postclassic times Cholula continued as a major religious and cultural centre. Xochicalco probably was of minor significance in Early Classic times; but it went through a phase of explosive growth in the Late Classic and was probably abandoned by 1200, possibly earlier. Tula, on the other hand, a small centre in the Late Classic, went through a rapid growth during the period 900–1200 and then declined to a provincial centre in the Late Postclassic. There is a strong suggestion that the demise of Classic Teotihuacán was in part related to the emergence of one or all of these major centres.