If any region can be described as a “heartland of cities” for ancient Mesoamerica, it is the Central Highlands of Mexico. This region is famous for many of the greatest metropoles of the Precolumbian Americas, including Teotihuacan, Cholula, Tula, and Tenochtitlan (Fig. 8.1). Although these great cities had their heydays in the Classic and Postclassic periods, the roots of urbanism lie in the Formative period when early cities developed throughout Central Mexico, including the Basin of Mexico, Tlaxcala, and Puebla (Carballo 2016). As with the other chapters in this volume, understanding Classic period urbanism in Central Mexico requires that we examine the growth and expansion of central places, beginning with the Early Formative and tracing the development of intensive sociopolitical and ideological interactions.